Low molecular weight peptidomimetic growth hormone secretagogues Number:7,094,869 from the United States Patent and Trademark Office (PTO) owispatent The present invention comprises growth hormone releasing peptides/peptidomimetics (GHRP) capable of causing release of growth hormone from the pituitary. Compositions containing the GHRP's of this invention are used to promote growth in mammals either alone or in combination with other growth promoting compounds, especially IGF-1. In a method of this invention GHRP's in combination with IGF-1 are used to treat Type II diabetes. An exemplary compound of this invention is provided below ##STR00001##<H peptidomimetic, secretagogues, Low, molecular, w, 7094869.html, Patent, pto, 7094869

Title: Low molecular weight peptidomimetic growth hormone secretagogues

Abstract: The present invention comprises growth hormone releasing peptides/peptidomimetics (GHRP) capable of causing release of growth hormone from the pituitary. Compositions containing the GHRP's of this invention are used to promote growth in mammals either alone or in combination with other growth promoting compounds, especially IGF-1. In a method of this invention GHRP's in combination with IGF-1 are used to treat Type II diabetes. An exemplary compound of this invention is provided below ##STR00001##

Patent Number: 7,094,869 Issued on 08/22/2006 to Somers, et al.

Inventors: Somers; Todd C. (Foster City, CA), Elias; Kathleen A. (San Francisco, CA), Clark; Ross G. (Pacifica, CA), McDowell; Robert S. (San Francisco, CA), Stanley; Mark S. (Pacifica, CA), Burnier; John P. (Pacifica, CA), Rawson; Thomas E. (Mountain View, CA)
Assignee: Genentech, Inc. (South San Francisco, CA)

Appl. No.: 10/224,640

Filed: August 19, 2002

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
09316505	May., 1999
09057074	Apr., 1998	6034216
08340767	Nov., 1994	5798337

Current U.S. Class: 530/331 ; 530/330

Current International Class: C07K 5/08 (20060101)

Field of Search: 530/331,330 514/17,18

References Cited [Referenced By]

U.S. Patent Documents


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4223020	September 1980	Momany
4223021	September 1980	Momany
4224313	September 1980	Zimmerman et al.
4224316	September 1980	Momany
4226857	October 1980	Momany
4228155	October 1980	Momany
4228156	October 1980	Momany
4228157	October 1980	Momany
4228158	October 1980	Momany
4410512	October 1983	Bowers
4410513	October 1983	Momany
4411890	October 1983	Momany
4839344	June 1989	Bowers et al.
4880777	November 1989	Momany
5206235	April 1993	Fisher et al.
5246920	September 1993	Bercu et al.
5268360	December 1993	Yoshikawa et al.
5283241	February 1994	Bochis et al.
5663146	September 1997	Bowers et al.
5663171	September 1997	Chen et al.
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WO 89/10933	Nov., 1989	WO
WO 92/01711	Feb., 1992	WO
WO 03/04081	Mar., 1993	WO
WO 94/08583	Apr., 1994	WO
WO 94/11012	May., 1994	WO
WO 94/13696	Jun., 1994	WO
WO 95/11029	Apr., 1995	WO
WO 95/13069	May., 1995	WO
WO 95/14666	Jun., 1995	WO
WO 95/17423	Jun., 1995	WO
WO 95/34311	Dec., 1995	WO
WO 96/10040	Apr., 1996	WO
WO 96/22997	Aug., 1996	WO
WO 99/36431	Jul., 1999	WO
WO 00/09537	Feb., 2000	WO

Other References

Chen, Shui Tein, Journal of the Chinese Chemical Society (Taipei, Taiwan) 37(3), 299-305, 1990. cited by examiner .
Bowers et al., "On the in Vitro and in Vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone" Endocrinology 114 (5) :1537-1545 (1984). cited by other .
Bowers et al., "Structure-activity relationships of a synthetic pentapeptide that specifically releases growth hormons in Vitro" Endocrinology 106 (3):663-667 (1980). cited by other .
Bowers, C. Y., "GH Releasing Peptides--Structure and Kinetics" J. Pediatr. Endocrinology 6(1):21-31 (1993). cited by other .
Deghenghi et al., "GH-Releasing Activity of Hexarelin, A New Growth Hormone Releasing Peptide, in Infant and Adult Rats" Life Sciences 54(18):1321-1328 (1994). cited by other .
Egorova et al., "Synthesis of shortened analogs of substance P with modification of the glutamine residue at position 6" Chemical Abstracts (abstract only) 116(11):abstract No. 106743 (1992). cited by other .
Lin, Tsau-Yen et al., "Inhibition of cathepsin D by synthetic oligopeptides" Chemical Abstracts (abstract only) 92(1):abstract No. 2280 (1980). cited by other .
Lin, Tsau-Yen et al., "Inhibition of Cathepsin D by Synthetic Oligopeptides" Journal of Biological Chemistry 254(23):11875-11883 (1979). cited by other .
Momany et al., "Conformational energy studies and in Vitro and in Vivo activity data on growth hormone-releasing peptides" Endocrinology 114(5):1531-1536 (1984). cited by other .
Momany et al., "Design, synthesis and biological activity of peptides which release growth hormone in Vitro" Endocrinology 108(1):31-39 (1981). cited by other .
Schoen et al., "Growth Hormone Secretagogues" Annual Reports in Medicinal Chemistry: Section IV-Immunology, Endocrinology & Metabolic Diseases, William K. Hagmann, Chapter 19, vol. 28:177-186 (1993). cited by other .
Schoen, W.R. et al., "Structure-activity relationships in the amino acid sidechain of L-692,429" Bioorg & Medicinal Chem. Lett. 4(9):1117-1122 (1994). cited by other .
Smith. R.G. et al., "A nonpeptidyl growth hormone secretagogue" Science 260:1640-1643 (1993). cited by other .
Stavropoulos et al., "Synthesis of potent agonists of Substance P by replacement of Metil with Glu(OBzl) and N-terminal glutamine with Glp of the C-terminal hexapeptide and heptapeptide of Substance P" Int. J. Peptide Protein Res. 45(6):508-513 (1995). cited by other .
Wu, Danxing et al., "The effect of GH-releasing peptide-2 (GHRP-2 or KP 102) on GH secretion from primary cultured ovine pituitary cells can be abolished by a specific GH-releasing factor (GRF) receptor antagonist" J. of Endocrinology, 148:R9-R13 (1994). cited by other.

Primary Examiner: Lukton; David
Attorney, Agent or Firm: Evans; David W

Parent Case Text

This application is a continuation of Ser. No. 09/316,505, filed May 21, 1999, now abandoned, which is a continuation of Ser. No. 09/057,074, filed Apr. 8, 1998, now U.S. Pat. No. 6,034,216. application Ser. No. 09/057,074 is a continuation of Ser. No. 08/340,767 filed Nov. 16, 1994, now U.S. Pat. No. 5,798,337.

Claims

What is claimed is:

1. The compound represented by structural Formula (IV) ##STR00130## where Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, ##STR00131## Ar.sup.3 is selected from the group ##STR00132## n and o are independently 1, 2 or 3; R.sup.A is selected from the group C.sub.0-C.sub.3alkyl-heterocycle where the heterocycle comprises a mono-, bi-, or tricycle containing 5-12 ring atoms, one or two of which are heteroatoms selected from O, S, and N, provided at least one heteroatom is N, where any N atom is optionally substituted with R.sup.1, C.sub.0-C.sub.6alkyl substituted with one or two substituents selected from the group NR.sup.2R.sup.3, imidazolinyl, pyridinyl, dihydropyridinyl, and piperidinyl; R.sup.B, R.sup.C, R.sup.D, and R.sup.E are selected from the group hydrogen, C.sub.1-C.sub.6alkyl optionally substituted with a group selected from NR.sup.2R.sup.3, and phenyl-C.sub.1-C.sub.3--NR.sup.2R.sup.3, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl; R.sup.1 is selected from hydrogen, C.sub.1-C.sub.6alkyl, C(.dbd.O)--C.sub.1-C.sub.6alkyl, C(.dbd.O)--NR.sup.2R.sup.3, C(.dbd.NR.sup.2)--NR.sup.2R.sup.3, C(.dbd.O)O--C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl; R.sup.2 and R.sup.3 are independently selected from hydrogen, C.sub.1-C.sub.6alkyl, piperidinyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl; R.sup.2 and R.sup.3 together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.6 and where the heterocycle is optionally fused to a phenyl ring, optionally substituted with R.sup.4; R.sup.4 and R.sup.5 are independently selected from the group hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.6alkyl optionally substituted with 1-3 R.sup.6, C.sub.2-C.sub.6alkynyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxy optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6acylamino optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkylcarbonyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxycarbonyl optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl), N--(C.sub.1-C.sub.6acyl)amino optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.0-C.sub.6alkyl)amino optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy; R.sup.6 is selected from the group COOR.sup.2, CONR.sup.2R.sup.3, O(C.dbd.O)R.sup.2, cyano, NR.sup.2R.sup.3, NR.sup.2COR.sup.3, azido, nitro, and hydroxy; R.sup.7 is selected from the group R.sup.6, and C.sub.6-C.sub.10aryl optionally substituted with halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy; Z is selected from the group C.sub.1-C.sub.6alkyl substituted with 1-2 R.sup.7, C.sub.2-C.sub.6alkynyl optionally substituted with 1-2R.sup.7, C.sub.2-C.sub.6alkyenyl optionally substituted with 1-2 R.sup.7, and C.sub.1-C.sub.6alkyloxy optionally substituted with 1-2 R.sup.7, Z and R.sup.E together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.7 and where the heterocycle is optionally fused to a phenyl ring; and pharmaceutically acceptable salts thereof.

2. The compound of claim 1 selected from the group ##STR00133## ##STR00134## ##STR00135## ##STR00136## pharmaceutically acceptable salts thereof.

3. The compound of claim 1 represented by structural Formula (IVa) ##STR00137## where R.sup.B, R.sup.C, R.sup.D and R.sup.E are selected from the group hydrogen, and C.sub.1-C.sub.6alkyl; Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, and ##STR00138## Ar.sup.3 is selected from the group ##STR00139## R.sup.F is selected from the group OH, C.sub.1-C.sub.4alkyloxy, NR.sup.5R.sup.6, and 1 to 4 .alpha.-amino acid residues; R.sup.4 is selected from hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy; R.sup.5 and R.sup.6 are independently selected from hydrogen, and C.sub.1-C.sub.6alkyl; and pharmaceutically acceptable salts thereof.

4. The compound of claim 3 selected from the group ##STR00140## ##STR00141## pharmaceutically acceptable salts thereof.

Description

FIELD OF THE INVENTION

The invention relates to synthetic peptidomimetics having growth hormone releasing activity in mammals. The peptidomimetics of this invention are used to stimulate the release of endogenous growth hormone (GH) in mammals needing elevation of serum growth hormone levels.

BACKGROUND OF THE INVENTION

GH secretion is known to be inhibited by the hypothalamic hormone somatostatin (SS) and stimulated by GH-releasing hormone (GHRH) in all mammalian species studied including humans. In man, GH is released from the anterior pituitary somatotrophs in pulsatile secretory bursts occurring about 4-8 times in each 24 hour period (Devesa, J., et al., Trends Endocrinol Metab. 3:175-183 [1992] and Mason, W. T., et al., Acta Paediatr Suppl 388:84-92 [1993]). This episodic release pattern seems to be optimal for inducing the physiological effects of GH since many target tissues appear to be more sensitive to the frequency than the total amount of GH arriving at the target tissue (Robinson and Clark Growth Hormone: Basic and Clinical Aspects Isaksson, Binder, Hall and Hokfelt eds., Amsterdam, p109-127 [1987]). It is believed the episodic secretion of GH is caused by the rhythmic alternate release of the excitatory 44-amino acid peptide GHRH and the inhibitory tetradecapeptide SS, regulated through the "pituitary-hypothalamus axis" (see FIG. 1). Secreted GH, in turn, both directly and indirectly through IGF-1 appears to maintain this rhythm by stimulating SS and inhibiting GHRH release. Other neurotransmitters also modulate GH release usually by stimulating or inhibiting SS release. Additionally, other factors including exercise, sleep, glucocorticoids, thyroid hormones (e.g. TSH), sex steroids (e.g. testosterone and 17-.beta. estradiol), free fatty acids, amino acids (e.g. arginine and ornithine), and glucose levels further modulate GH release.

In addition to the two primary endogenous regulators of GH release, SS and GHRH, a number of other peptidyl/nonpeptidyl compounds have been shown to stimulate GH release primarily through the pituitary-hypothalamus axis. These include the peptides galanin, pituitary adenylate cyclase-activation peptide (PACAP), delta sleep-inducing peptide (DSIP), and angiotensin II. These peptides, however, generally lack specificity for GH release. A number of structurally diverse nonpeptidyl GH secretagogues (e.g. Talipexole and Clonidine) are reported to stimulate GH release in vitro and in vivo, but these compounds are believed to mediate their effect through cholinergic, adrenergic, dopaminergic or serotonergic pathways and thus also lack GH releasing specificity.

Apart from GHRH, the GH secretagogues having the greatest GH releasing specificity and thus having the greatest therapeutic potential are the growth hormone releasing peptides/peptidomimetics (GHRP's) (Bowers, J. Pediatr. Endocrinol. 6:21-31 [1993]; and Schoen et al., Annual Reports in Medicinal Chemistry, 28:177-186 [1993]). These compounds can activate the pituitary-hypothalamus axis (Dickson et al., Neuroscience 53:303-306 [1993]) and act directly on the pituitary somatotroph (see FIG. 1) by an independent (non-GHRH, non-opiate and non-SS) secretory pathway. Compounds of this class can therefore be characterized by their independent GH releasing pathway. For example, somatotroph cells maximally stimulated with GHRP's can release additional GH when treated with GHRH and vice versa. Similarly the inhibitory effects of specific antagonists to GHRH or GHRP's have no effect on stimulation of GH release by the opposite secretagogue in vitro. These compounds also exhibit dose-dependent desensitization or attenuation of GH release after continuous exposure with the same or different compounds of the GHRP class. Furthermore, structurally related biologically inactive cognate GHRP compounds capable of inhibiting GH release of a particular GHRP have no effect on GHRH agonism. These effects support the independent pathway model and serve as experimental criteria for compounds belonging to the GHRP class. Surprisingly, while the GHRH receptor has been cloned in a number of species including man (Gaylin et al., Mol. Endo. 7:77-84 [1993], the GHRP receptor has remained elusive.

The paradigm compounds of the GHRP class are the synthetic methionine-enkephalin derived GHRP's identified by Bowers et al., Endocrinology 106:663-667 (1980) and Momany et al., Endocrinology 108:31-39 (1981). The most widely studied GHRP is referred to as "GHRP-6" (Momany et al., Endocrinology 114:1531-1536 [1984]; and Bowers et al., Endocrinology 114:1537-1545 [1984]) which has been shown; to be specific for GH release, has no reported long term toxicity, is well tolerated, and can elevate serum GH in a dose-dependent manner in normal humans (Bowers, J. Pediatr. Endocrinol. 6:21-31 [1993]). GHRP-6 is active in a dose-dependent manner when administered either iv, intranasally or orally, though it is poorly absorbed orally (.about.0.3%). More potent second generation hepta- and hexapeptides, "GHRP-1" and "GHRP-2" (also known as KP 102), of this class have been described more recently, though these compounds are also expected to be poorly absorbed orally.

His-D Trp-Ala-Trp-D Phe-Lys-NH.sub.2

(HwAWfK-NH2)

GHRP-6

Ala-His-D .beta.Nal-Ala-Trp-D Phe-Lys-NH.sub.2

(AHbAWfK-NH2)

GHRP-1

D Ala-D .beta.Nal-Ala-Trp-D Phe-Lys-NH.sub.2

(abAWfK-NH2)

GHRP-2

More recently, nonpeptidyl benzolactam GH secretagogues that appear to use the same alternative signal transduction pathway as GHRP-6 have been described (Smith, R. G. et al., Science 260:1640-1643 [1993] and U.S. Pat. No. 5,206,235). The benzolactam L-692,429 in combination with GHRP-6 at concentrations that maximally stimulated GH release produced no additional GH release. Conversely, GHRH and L-692,429 were reported to give a synergistic increase in GH secretion. GHRH and L-692,429 were also reported to effect a common transient desensitation pattern indicating these compounds opperate through a common receptor pathway. L-692,429 is reported to be about 6-fold less potent that GHRP-6 and to be specific for GH release, except for some in vivo ACTH and cortisol release. ##STR00002##

A more potent analogue of L-692,429 having a potency in the rat pituitary cell assay slightly greater than GHRP-6 has also been reported (Schoen W. R. et al., Bioorg. & Medicinal Chem. Lett. 4:1117-1122 [1994]). This compound, L-692,585, presumably causes GH release by the same alternative pathway as GHRP-6. ##STR00003##

A number of these compounds (e.g., "GHRP-6" and L-692,429) are reported to be safe and effective in promoting endogenous GH release in humans, however, there remain problems with oral availability and specificity.

OBJECTS OF THE INVENTION

It is an object of this invention to provide novel GH secretagogues that promote the release of endogenous growth hormone in mammals. It is a further object to provide GH secretagogues that provide a synergistic increase in GH secretion when combined with GHRH. It is still a further object of this invention to provide more potent GH secretagogues than those of the prior art, especially "GHRP-6", "GHRP-1", "GHRP-2", L-692,429 and L-692,585. It is a further object to provide GH secretagogues that are specific for GH release and do not cause significant release of other hormones, especially; LH, FSH, TSH, ACTH, prolactin, vasopressin, oxytocin, insulin and cortisol.

These and other objects of the invention will be apparent from the following specification.

SUMMARY OF THE INVENTION

The objects of this invention have been achieved by providing a compound represented by structural formula (I): ##STR00004##

where the symbols in formula (I) define the following groups:

A is selected from ##STR00005## and C.sub.1-C.sub.6alkyl substituted with ##STR00006##

B may optionally be selected from the group a covalent bond, and C.sub.1-C.sub.3alkyl, when L.sup.2 is --N(R.sup.C)--Q;

C is selected from the group hydrogen, ##STR00007## D-Y, and ##STR00008##

D is selected from the group ##STR00009## and C.sub.1-C.sub.6alkyl substituted with ##STR00010##

E is selected from the group ##STR00011## and C.sub.1-C.sub.6alkyl substituted with ##STR00012##

Ar.sup.1 and Ar.sup.2 are each independently selected from substituted or unsubstituted aryl and substituted or unsubstituted heterocycle, preferably indoyl substituted with (R.sup.4).sub.n, ##STR00013## and ##STR00014##

Ar.sup.1 and Ar.sup.2 are independently selected from hydrogen, and C.sub.1-C.sub.6alkyl;

when R.sup.B or R.sup.C are L.sup.1--Ar.sup.1 or L.sup.2--Ar.sup.2;

Ar.sup.3 is selected from the group ##STR00015## and ##STR00016##

Ar.sup.3 is selected from hydrogen, and C.sub.1-C.sub.6alkyl;

when R.sup.D is L.sup.3-Ar.sup.3;

Ar.sup.1 together with a, Ar.sup.2 together with b and Ar.sup.3 together with c, each pair together with the carbon to which they are attached may independently form a 5 or 6 member carbocyclic ring;

a, b and c are independently selected from hydrogen, and C.sub.1-C.sub.6alkyl;

n and o are independently 1, 2 or 3;

L.sup.1 is selected from --CH.sub.2--O--, --CH.sub.2--CH.sub.2--O--, --CH.sub.2--, --CH.sub.2--CH.sub.2--, and --CH.sub.2--CH.sub.2--CH.sub.2--;

L.sup.2 and L.sup.3 are independently selected from a covalent bond, --O--, --O--CH.sub.2--, --N(R.sup.C)--Q, and L.sup.1;

Q is selected from the group --L.sup.2--, --S(.dbd.O).sub.2--L.sup.2--, --C(.dbd.O)--, --C(.dbd.O)--O--, --CH(X)--, and --CH(X)--CH.sub.2--;

R.sup.A is selected from the group C.sub.0-C.sub.3alkyl-heterocycle where the heterocycle comprises a mono-, bi-, or tricycle containing 5-12 ring atoms, one or two of which are heteroatoms selected from O, S, and N, provided at least one heteroatom is N, where any N atom is optionally substituted with R.sup.1, C.sub.0-C.sub.6alkyl substituted with one or two substituents selected from the group NR.sup.2R.sup.3, imidazolinyl, pyridinyl, dihydropyridinyl, and piperidinyl;

R.sup.B, R.sup.C and R.sup.D are selected from the group R.sup.A, L.sup.1--Ar.sup.1, L.sup.2--Ar.sup.2, hydrogen, C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.A and R.sup.B together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional heteroatom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.6 and where the heterocycle is optionally fused to a phenyl ring, optionally substituted with R.sup.4;

R.sup.1 is selected from hydrogen, C.sub.1-C.sub.6alkyl, C(.dbd.O)--C.sub.1-C.sub.6alkyl, C(.dbd.O)--NR.sup.2R.sup.3, C(.dbd.NR.sup.2)--NR.sup.2R.sup.3, C(.dbd.O)O--C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl, hydroxyC.sub.1-C.sub.6alkyl, dihydroxyC.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 are independently selected from R.sup.1 and piperidinyl;

R.sup.2 and R.sup.3 together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.6 and where the heterocycle is optionally fused to a phenyl ring, optionally substituted with R.sup.4;

R.sup.4 and R.sup.5 are independently selected from the group hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.6alkyl optionally substituted with 1-3 R.sup.6, C.sub.2-C.sub.6alkynyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxy optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6acylamino optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkylcarbonyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxycarbonyl optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl), N--(C.sub.1-C.sub.6acyl)amino optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.0-C.sub.6alkyl)amino optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

R.sup.6 is selected from the group COOR.sup.2, O(C.dbd.O)R.sup.2, CONR.sup.2R.sup.3, cyano, NR.sup.2R.sup.3, NR.sup.2COR.sup.3, azido, nitro, and hydroxy;

R.sup.7 is selected from the group R.sup.6, C.sub.6-C.sub.10aryl optionally substituted with halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

X is selected from the group hydrogen, C.sub.0-C.sub.6alkyl optionally substituted with 1-3 R.sup.6, C.sub.0-C.sub.6alkyl-O--C.sub.1-C.sub.6alkyl optionally substituted with 1-2 R.sup.6, and C.sub.1-C.sub.6acyl optionally substituted with a group selected from L.sup.2--Ar.sup.2, R.sup.A, and R.sup.6;

Y is selected from the group --(C.dbd.O)--R.sup.A, C.sub.1-C.sub.6alkyl substituted with 1-2 R.sup.7, C.sub.2-C.sub.6alkynyl optionally substituted with 1-2R.sup.7, C.sub.2-C.sub.6alkyenyl optionally substituted with 1-2 R.sup.7, and C.sub.1-C.sub.6alkyloxy optionally substituted with 1-2 R.sup.7,

Y and R.sup.D together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.7 and where the heterocycle is optionally fused to a phenyl ring;

Z is selected from the group C.sub.1-C.sub.6alkyl substituted with 1-2 R.sup.7, C.sub.2-C.sub.6alkynyl optionally substituted with 1-2R.sup.7, C.sub.2-C.sub.6alkyenyl optionally substituted with 1-2 R.sup.7, C.sub.1-C.sub.6alkyloxy optionally substituted with 1-2 R.sup.7 and piperidinyl; and pharmaceutically acceptable salts thereof.

In one embodiment of the invention the compound preferably has a molecular weight between 400-650 da and is represented by formula II ##STR00017## where the symbols in formula II are defined as follows:

Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, ##STR00018## and ##STR00019##

n and o are independently 1, 2 or 3;

L.sup.1 is selected from --CH.sub.2--O, --CH.sub.2--CH.sub.2--O-- --CH.sub.2--, --CH.sub.2--CH.sub.2--, and --CH.sub.2--CH.sub.2--CH.sub.2--;

L.sup.2 is selected from a covalent bond, --O--, and L.sup.1;

R.sup.A is selected from the group C.sub.0-C.sub.3alkyl-heterocycle, --O--C.sub.0-C.sub.3alkyl-heterocycle, and --NR.sup.2--C.sub.2-C.sub.6alkyl-heterocycle, where the heterocycle comprises a mono-, bi-, or tricycle containing 5-12 ring atoms, one or two of which are heteroatoms selected from O, S, and N, provided at least one heteroatom is N, where any N atom is optionally substituted with R.sup.1, C.sub.0-C.sub.6alkyl substituted with one or two substituents, O--C.sub.2-C.sub.6alkyl substituted with one or two substituents, and NR.sup.2--C.sub.2-C.sub.6alkyl substituted with one or two substituents where the substituents are selected from the group NR.sup.2R.sup.3, imidazolinyl, pyridinyl, dihydropyridinyl, and piperidinyl;

R.sup.B and R.sup.C are selected from the group hydrogen, C.sub.1-C.sub.6alkyl optionally substituted with a group selected from NR.sup.2R.sup.3, and phenyl-C.sub.1-C.sub.3--NR.sup.2R.sup.3, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.1 is selected from hydrogen, C.sub.1-C.sub.6alkyl, C(.dbd.O)--C.sub.1-C.sub.6alkyl, C(.dbd.O)--NR.sup.2R.sup.3, C(.dbd.NR.sup.2)--NR.sup.2R.sup.3, C(.dbd.O)O--C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxyalkyl or (hydroxylalkyl);

R.sup.2 and R.sup.3 are independently selected from hydrogen, C.sub.1-C.sub.6alkyl, piperidinyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.6 and where the heterocycle is optionally fused to a phenyl ring, optionally substituted with R.sup.4;

R.sup.4 and R.sup.5 are independently selected from the group hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.6alkyl optionally substituted with 1-3 R.sup.6, C.sub.2-C.sub.6alkynyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxy optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6acylamino optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkylcarbonyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxycarbonyl optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl), N--(C.sub.1-C.sub.6acyl)amino optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.0-C.sub.6alkyl)amino optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

R.sup.6 is selected from the group COOR.sup.2, O(C.dbd.O)R.sup.2, CONR.sup.2R.sup.3, cyano, NR.sup.2R.sup.3, NR.sup.2COR.sup.3, azido, nitro, and hydroxy;

X is selected from the group hydrogen, oxo (.dbd.O), COOR.sup.2, CONR.sup.2R.sup.3, C.sub.0-C.sub.6alkyl-O--C.sub.1-C.sub.6alkyl optionally substituted with 1-2 R.sup.6, and C.sub.1-C.sub.6alkyl optionally substituted with 1-2 R.sup.6; and pharmaceutically acceptable salts thereof.

Alternative compounds of this embodiment may be represented by formula IIa-IIg ##STR00020##

where Ar.sup.1, Ar.sup.2, R.sup.B, R.sup.C, R.sup.1, R.sup.2, R.sup.3, R.sup.6, Q and X are defined above, and p is 0, 1 or 2.

Optionally the Ar.sup.1, Ar.sup.2, R.sup.B, R.sup.C, R.sup.1, R.sup.2, R.sup.3, R.sup.6 and X are defined as follows:

Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, and ##STR00021##

R.sup.B and R.sup.C are selected from the group hydrogen, and methyl;

R.sup.1 is selected from hydrogen, C.sub.1-C.sub.6alkyl, C.sub.2-C.sub.6alkyl substituted with 1 or 2 hydroxy groups, C(.dbd.O)--C.sub.1-C.sub.6alkyl, C(.dbd.O)--NR.sup.2R.sup.3, C(.dbd.NR.sup.2)--NR.sup.2R.sup.3, C(.dbd.O)O--C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 are independently selected from hydrogen, C.sub.1-C.sub.6alkyl, piperidinyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 together with the nitrogen to which they are attached may form piperidinyl, pyrroylidinyl, piperazinyl, and morpholinyl;

R.sup.6 is selected from the group COOR.sup.2, O(C.dbd.O)R.sup.2, CONR.sup.2R.sup.3, cyano, NR.sup.2R.sup.3, NR.sup.2COR.sup.3, azido, nitro, and hydroxy;

X is selected from the group hydrogen, oxo (.dbd.O), COOR.sup.2, CONR.sup.2R.sup.3, C.sub.0-C.sub.6alkyl-O--C.sub.1-C.sub.6alkyl optionally substituted with 1-2 R.sup.6, and C.sub.1-C.sub.6alkyl optionally substituted with 1-2 R.sup.6; and pharmaceutically acceptable salts thereof.

In an alternative embodiment of the invention the compound is represented by structural formula III-IIIi ##STR00022## ##STR00023##

where the symbols in formula III-IIIi are defined as follows:

Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, ##STR00024## and ##STR00025##

n and o are independently 1, 2 or 3;

L.sup.1 and L.sup.2 are independently selected from --CH.sub.2--O--, --CH.sub.2--CH.sub.2--CH.sub.2--O-- --CH.sub.2--, --CH.sub.2--CH.sub.2--, and --CH.sub.2--CH.sub.2--CH.sub.2--;

R.sup.A is selected from the group C.sub.0-C.sub.3alkyl-heterocycle, --O--C.sub.0-C.sub.3alkyl-heterocycle, and --NR.sup.2--C.sub.2-C.sub.6alkyl-heterocycle, where the heterocycle comprises a mono-, bi-, or tricycle containing 5-12 ring atoms, one or two of which are heteroatoms selected from O, S, and N, provided at least one heteroatom is N, where any N atom is optionally substituted with R.sup.1, C.sub.0-C.sub.6alkyl substituted with one or two substituents, O--C.sub.2-C.sub.6alkyl substituted with one or two substituents, and NR.sup.2--C.sub.2-C.sub.6alkyl substituted with one or two substituents where the substituents are selected from the group NR.sup.2R.sup.3, imidazolinyl, pyridinyl, dihydropyridinyl, and piperidinyl;

R.sup.B, R.sup.C and R.sup.D are selected from the group hydrogen, C.sub.1-C.sub.6alkyl optionally substituted with a group selected from NR.sup.2R.sup.3, and phenyl-C.sub.1-C.sub.3--NR.sup.2R.sup.3, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.1 is selected from hydrogen, C.sub.1-C.sub.6alkyl, C(.dbd.O)--C.sub.1-C.sub.6alkyl, hydroxyalkyl C(.dbd.O)--NR.sup.2R.sup.3, C(.dbd.NR.sup.2)--NR.sup.2R.sup.3, C(.dbd.O)O--C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 are independently selected from hydrogen, C.sub.1-C.sub.6alkyl, piperidinyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.6 and where the heterocycle is optionally fused to a phenyl ring, optionally substituted with R.sup.4;

R.sup.4 and R.sup.5 are independently selected from the group hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.6alkyl optionally substituted with 1-3 R.sup.6, C.sub.2-C.sub.6alkynyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxy optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6acylamino optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkylcarbonyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxycarbonyl optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl), N--(C.sub.1-C.sub.6acyl)amino optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.0-C.sub.6alkyl)amino optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

R.sup.6 is selected from the group COOR.sup.2, O(C.dbd.O)R.sup.2, CONR.sup.2R.sup.3, cyano, NR.sup.2R.sup.3, NR.sup.2COR.sup.3, azido, nitro, and hydroxy;

R.sup.7 is selected from the group R.sup.6, and C.sub.6-C.sub.10aryl optionally substituted with halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

Y is selected from the group C.sub.1-C.sub.6alkyl substituted with 1-2 R.sup.7, C.sub.2-C.sub.6alkynyl optionally substituted with 1-2R.sup.7, C.sub.2-C.sub.6alkyenyl optionally substituted with 1-2 R.sup.7, and C.sub.1-C.sub.6alkyloxy optionally substituted with 1-2 R.sup.7, and pharmaceutically acceptable salts thereof.

In a further alternative embodiment of this invention the compound is represented by structural formula IV ##STR00026##

where the symbols of formula IV are defined as follows:

Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, ##STR00027## and ##STR00028##

Ar.sup.3 is selected from the group ##STR00029## and ##STR00030##

n and o are independently 1, 2 or 3;

R.sup.A is selected from the group C.sub.0-C.sub.3alkyl-heterocycle, --O--C.sub.0-C.sub.3alkyl-heterocycle, and --NR.sup.2--C.sub.2-C.sub.6alkyl-heterocycle, where the heterocycle comprises a mono-, bi-, or tricycle containing 5-12 ring atoms, one or two of which are heteroatoms selected from O, S, and N, provided at least one heteroatom is N, where any N atom is optionally substituted with R.sup.1, C.sub.0-C.sub.6alkyl substituted with one or two substituents, O--C.sub.2-C.sub.6alkyl substituted with one or two substituents, and NR.sup.2--C.sub.2-C.sub.6alkyl substituted with one or two substituents where the substituents are selected from the group NR.sup.2R.sup.3, imidazolinyl, pyridinyl, dihydropyridinyl, and piperidinyl;

R.sup.B, R.sup.C, R.sup.D, and R.sup.E are selected from the group hydrogen, C.sub.1-C.sub.6alkyl optionally substituted with a group selected from NR.sup.2R.sup.3, and phenyl-C.sub.1-C.sub.3--NR.sup.2R.sup.3, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.1 is selected from hydrogen, C.sub.1-C.sub.6alkyl, C(.dbd.O)--C.sub.1-C.sub.6alkyl, C(.dbd.O)-hydroxyalkyl NR.sup.2R.sup.3, C(.dbd.NR.sup.2)--NR.sup.2R.sup.3, C(.dbd.O)O--C.sub.1-C.sub.6alkyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 are independently selected from hydrogen, C.sub.1-C.sub.6alkyl, piperidinyl, and halo(F, Cl, Br, I)C.sub.1-C.sub.6alkyl;

R.sup.2 and R.sup.3 together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.6 and where the heterocycle is optionally fused to a phenyl ring, optionally substituted with R.sup.4;

R.sup.4 and R.sup.5 are independently selected from the group hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.6alkyl optionally substituted with 1-3 R.sup.6, C.sub.2-C.sub.6alkynyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxy optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6acylamino optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkylcarbonyl optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.6alkyloxycarbonyl optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl), N--(C.sub.1-C.sub.6acyl)amino optionally substituted with 1-3 R.sup.6, N--(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.0-C.sub.6alkyl)amino optionally substituted with 1-3 R.sup.6, N,N-di(C.sub.1-C.sub.6alkyl)carboxamido optionally substituted with 1-3 R.sup.6, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

R.sup.6 is selected from the group COOR.sup.2, O(C.dbd.O)R.sup.2, CONR.sup.2R.sup.3, cyano, NR.sup.2R.sup.3, NR.sup.2COR.sup.3, azido, nitro, and hydroxy;

R.sup.7 is selected from the group R.sup.6, C.sub.6-C.sub.10aryl optionally substituted with halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

Z is selected from the group C.sub.1-C.sub.6alkyl substituted with 1-2 R.sup.7, C.sub.2-C.sub.6alkynyl optionally substituted with 1-2R.sup.7, C.sub.2 -C.sub.6alkyenyl optionally substituted with 1-2 R.sup.7, and C.sub.1-C.sub.6alkyloxy optionally substituted with 1-2 R.sup.7,

Z and R.sup.E together with the N to which they are bonded may form a 5- or 6-member heterocycle, optionally containing one additional hetero atom selected from O, S, and N where any N is optionally substituted with R.sup.1, any carbon is optionally substituted with R.sup.7 and where the heterocycle is optionally fused to a phenyl ring; and pharmaceutically acceptable salts thereof.

An optional compound of this embodiment is represented by structural Formula (IVa) ##STR00031##

where the symbols in formula IVa are defined as follows:

R.sup.B, R.sup.C, R.sup.D and R.sup.E are selected from the group hydrogen, and C.sub.1-C.sub.6alkyl;

Ar.sup.1 and Ar.sup.2 are each independently selected from indoyl, and ##STR00032##

Ar.sup.3 is selected from the group ##STR00033## and ##STR00034##

R.sup.F is selected from the group OH, C.sub.1-C.sub.4alkyloxy, NR.sup.5R.sup.6, and 1 to 4 .alpha.-amino acid residues;

R.sup.4 is selected from hydrogen, halo(F, Cl, Br, and I), cyano, amino, amido, nitro, hydroxy, C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4perfluoroalkyl, and C.sub.1-C.sub.3perfluoroalkoxy;

R.sup.5 and R.sup.6 are independently selected from hydrogen, and C.sub.1-C.sub.6alkyl; and

pharmaceutically acceptable salts thereof.

In still another embodiment of this invention the compound is referred to as a "retroinverso" of the compound of formula II and is represented by formula V ##STR00035##

where Ar.sup.1, Ar.sup.2, L.sup.1, L.sup.2, R.sup.A, R.sup.B, R.sup.C and X are defined above for the compound of formula I.

The invention further comprises a pharmaceutical composition comprising a pharmaceutically acceptable excipient and any of the compounds represented by structural formula I-V. Additionally the invention provides a method for increasing the level of endogenous growth hormone in a mammal comprising administering to the mammal a pharmaceutically effective amount of the forgoing composition to the mammal. The method further comprises administering the composition in combination with a growth factor selected from; growth hormone releasing hormone (GHRH), insulin like growth factor-1 (IGF-1), and insulin like growth factor-2 (IGF-2). In an alternative method of this invention GHRP's represented by formulae I-V, as well as other GHRP's, are used in combination with IGF-1 to treat diseases in which long term IGF-1 is indicated including but not limited to Type II diabetes.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. A cartoon showing regulation of growth hormone (GH) release by the "pituitary-hypothalamus axis" and the alternative "GHRP pathway". Some of the stimulatory (+) and inhibitory (-) effects that growth hormone releasing hormone/factor (GHRH/F), growth hormone releasing peptides/peptidomimetics (GHRP's), somatostatin (SS), GH, and insulin-like growth factor 1 (IGF-1) have on selected glands, organs, and tissues are also shown.

FIG. 2. A representative rat "pit" cell assay dose response of GH release over a 15 min. exposure to increasing concentrations of (inip)-bbFK-NH.sub.2. GH release is significantly (P<0.05) increased at 0.3 nM and reaches a plateau by 1 nM with an EC.sub.50 of 0.16 nM (see right panel for data points and curve used to calculate EC.sub.50). The mean (n=3) EC.sub.50 for inip-bbFK-NH.sub.2 was 0.18.+-.0.04 nM, over 30-fold more potent than HwAWfK-NH.sub.2 ("GHRP-6") (6.2.+-.1.5 nM; n=5).

FIG. 3. Demonstration that (inip)-bbFK-NH.sub.2 acts at the proposed "GHRP receptor". Rat "pit" cell challenges were carried out using combinations of GHRP-6, (inip)-bbFK-NH.sub.2 and GHRH. GHRP-6 and (inip)-bbFK-NH.sub.2 (100 nM) both caused 3-fold increases in GH levels over control (ctrl), but no additional or synergistic increase was observed when used in combination (solid black bars). In contrast, both GHRP-6 and (inip)-bbFK-NH.sub.2 show synergy with 10 nM GHRH indicating that neither GHRP-6 nor (inip)-bbFK-NH.sub.2 act via the GHRH receptor (cross hatched bars).

FIG. 4. Desensitization effect of the "GHRP receptor" upon challenging rat pituitary cells with three sequential 15 min. incubations with fresh (inip)-bbFK-NH.sub.2. The GH release was decreased after the second 15 min. incubation (total 30 min. exposure to (inip)-bbFK-NH.sub.2) and no significant GH release compared to control occurred during the final challenge with (inip)-bbFK-NH.sub.2. However when GHRH (10 nM) was added to the next 15 min. incubation, a significant GH response occurred, consistent with the separate receptor model.

FIG. 5. Somatostatin suppression of GHRP-stimulated GH release. (Inip)-bbFK-NH.sub.2 at 0.1, 1, 10 and 100 nM significantly elevates GH release (solid black bars). Coincubation of (inip)-bbFK-NH.sub.2 with 20 nM somatostatin suppressed this release (crosshatched bars).

FIG. 6. Antagonism of (inip)-bbFK-NH.sub.2 induced GH release in the absence (solid black bars) and presence of 10 .mu.M of the "GHRP-6" antagonist HwkWfK-NH.sub.2 (crosshatched bars).

FIG. 7. Specificity for GH release compared to prolactin release induced with (inip)-bbFK-NH.sub.2. GH and prolactin levels in the same media from cells challenged with 100 nM (inip)-bbFK-NH.sub.2. GH release was 3-fold while prolactin levels increased 1.6 fold.

FIG. 8. TSH, FSH and LH release induced with (inip)-bbFK-NH.sub.2. Pituitary cells challenged with (inip)-bbFK-NH.sub.2 had no effect on these hormone concentrations.

FIG. 9. ACTH release induced with corticotrophin releasing factor (CRF) or (inip)-bbFK-NH.sub.2. ACTH levels rose 3-fold when stimulated with CRF but no significant change was observed with 100 nM (inip)bbFK-NH.sub.2.

FIGS. 10A-10D. Ca.sup.++ release in pituitary cells by (inip)bbFK-NH.sub.2. Basal Ca.sup.++ in Indol-1 AM loaded pituitary cells after 4-day monolayer culture (FIG. 10A and FIG. 10C). Twenty-one (21) seconds after (inip)bbFK-NH.sub.2 addition, the increased C.sup.++ flux in FIG. 10D is demonstrated by lighter areas in some of the cells of this heterologous population. Addition of vehicle did not change C.sup.++ levels (FIG. 10B).

FIG. 11. Dose dependent GH release with (inip)bb(feg). GH release by rat pituitary cells to increasing concentrations of (inip)bb(feg) (left panel) over a 15 minute incubation. Right panel shows data points and curve used to calculate the EC.sub.50 of 0.09 nM.

FIG. 12. Demonstration that (inip)bb(feg) acts at the proposed "GHRP receptor". GH response to GHRP-6 (100 nM) and (inip)bb(feg) (100 nM) was significantly greater than control but GH release was not synergistic when both were added in combination. GHRH (100 nM) elicited a mild GH response which was synergistic in combination with either GHRP-6 or (inip)bb(feg).

FIG. 13. Somatostatin suppression of (inip)bb(feg)-stimulated GH release. GH release with 100 nM (inip)bb(feg) was totally suppressed in the presence of 20 nM somatostatin.

FIG. 14. Desensitization of the "GHRP receptor" upon challenging rat pituitary cells with three sequential 15 min. incubations with fresh (inip)bb(feg). GH release from the same pituitary cells over three sequential 15 minute incubations with (inip)bb(feg) (100 nM). After a total of 45 minutes, GH release was markedly decreased in response to (inip)bb(feg) but these cells were able to release more GH in response to a final 15 minute incubation with GHRH (10 nM).

FIG. 15. Dose dependent GH release with (inip)b(wol). GH release by rat pituitary cells to increasing concentrations of (inip)b(wol) (left panel) over a 15 minute incubation. Right panel shows the data points and curve used to calculate the EC.sub.50 of 3.9 nM.

FIG. 16. Demonstration that (inip)b(wol) acts at the proposed "GHRP receptor". GH response to GHRP-6 (100 nM) and (inip)b(wol) (100 nM) was significantly greater than control but GH release was not synergistic when both were added in combination. GHRH (100 nM) elicited a mild GH response which was synergistic in combination with either GHRP-6 or (inip)b(wol).

FIG. 17. Somatostatin suppression of (inip)b(wol)-stimulated GH release. GH release to 100 nM (inip)b(wol) was totally suppressed in the presence of 20 nM somatostatin.

FIG. 18. Desensitization effect of the "GHRP receptor" upon challenging rat pituitary cells with three sequential 15 min. incubations with fresh (inip)b(wol). GH release from the same pituitary cells over three sequential 15 minute incubations with (inip)b(wol) (100 nM). After a total of 45 minutes, no significant release of GH was observed in response to (inip)b(wol) but these cells were able to release GH in response to a final 15 minute incubation with GHRH (10 nM).

FIG. 19. Body weight gain in normal adult female rats in response to excipient (open squares), three doses of (inip) b b F K-NH2 (4 .mu.g/d open circles, 20 .mu.g/d open triangles, 100 .mu.g/d half-filled diamonds), or one dose of GHRH (600 .mu.g/d, filled squares); delivery was by subcutaneous minipump infusion for 14 days. There was a dose-related weight gain in response to (inip) b b F K-NH2, that at 20 .mu.g/d reached the response to GHRH. Means and standard errors are shown.

FIG. 20. Body weight gain in normal adult female rats treated for 14 days with excipient (open bar), two doses of (inip) b b F K-NH2 given subcutaneously by injection (shaded bar, 100 .mu.g/d; solid bar, 20 .mu.g/d) or infusion (lightly hatched bar, 100 .mu.g/d; heavily hatched bar, 20 .mu.g/d). Injections of (inip) b b F K-NH2 were more effective than infusions. Means and standard errors are shown.

FIG. 21. Body weight gain in normal adult female rats treated for 14 days with excipient (open squares), or (inip) b b F K-NH2 given by subcutaneous injection (100 .mu.g/d; open triangles) or infusion (100 .mu.g/d; open circles). Injections of (inip) b b F K-NH2 produced a maintained growth response; infusions gave a large initial response that was not maintained. Means and standard errors are shown.

FIG. 22. Body weight gain in lean (open circles) and obese Type II Zucker Diabetic Fatty (ZDF) male rats treated subcutaneously for 24 days with excipient (solid circles), recombinant human growth hormone (rhGH, large open squares, 500 .mu.g/d), recombinant human insulin-like growth factor-1 (rhIGF-1, small squares, 758 .mu.g/d), (inip) b b F K-NH2 given by injection (100 .mu.g/d; open triangles), the combination of rhGH plus rhIGF-1 (solid squares), or the combination of rhIGF-1 plus (inip) b b F K-NH2 (solid triangles). The combination of (inip) b b F K-NH2 plus rhIGF-1 produced a maintained growth response equal to that of rhIGF-1 plus rhGH. Means and standard errors are shown.

FIG. 23. Body weight gain in obese Type II Zucker Diabetic Fatty (ZDF) male rats treated subcutaneously for 7 days with excipient (solid circles), recombinant human insulin-like growth factor-1 (rhIGF-1, open circles, 758 .mu.g/d), (inip) b b F K-NH2 given by injection (100 .mu.g/d; open triangles), or the combination of rhIGF-1 and (inip) b b F K-NH2 (solid triangles). The combination of (inip) b b F K-NH2 plus rhIGF-1 produced a maintained growth response that was at least additive compared to each agent given alone. Means and standard errors are shown.

FIG. 24. Basal blood glucose levels obtained weekly in lean (small squares) and obese Type II Zucker Diabetic Fatty (ZDF) male rats treated for 3 weeks subcutaneously with excipient (controls, solid circles), recombinant human growth hormone (rhGH, open squares, 500 .mu.g/d), recombinant human insulin-like growth factor-1 (rhIGF-1, open circles, 758 .mu.g/d), (inip) b b F K-NH2 given by injection (100 .mu.g/d; open triangles), or the combination of rhGH and rhIGF-1 (solid squares), or the combination of rhIGF-1 and (inip) b b F K-NH2 (solid triangles). When given alone, or in combination with rhIGF-1, (inip) b b F K-NH2 had lesser effect on blood glucose (diabetogenic effect) than rhGH at doses with similar somatogenic effects (FIG. 22). Means and standard errors are shown.

FIG. 25. Blood glucose concentrations following an intravenous insulin challenge (insulin tolerance test) in lean control male rats (open bar), obese Type II Zucker Diabetic Fatty (ZDF) rats treated subcutaneously with excipient (solid bar), recombinant human growth hormone (rhGH, light left-right ascending hatching, 500 .mu.g/d), recombinant human insulin-like growth factor-1 (rhIGF-1, light shaded bar, 758 .mu.g/d), (inip) b b F K-NH2 given by injection (100 .mu.g/d; light left-right descending hatching), or the combination of rhGH and rhIGF-1 (heavy left-right ascending hatching), or the combination of rhIGF-1 and (inip) b b F K-NH2 (heavy left-right descending hatching). When given alone, or in combination with rhIGF-1, (inip) b b F K-NH2 had a greatly reduced effect on insulin sensitivity (diabetogenic effect) than rhGH at doses with similar somatogenic effects (FIG. 22). Means and standard errors are shown.

FIG. 26. Daily body weight gains in normal adult female rats treated for 7 days with twice daily subcutaneous injections of excipient (open squares), growth hormone releasing hormone (open triangles), H w A W f K (solid squares), (inip) b b F-NH2 (open circles), (inip) b nmb barn (solid circles), or L-692,585 (solid triangles). Significant weight gain occurred after treatment with all molecules except L-692,585. Means and standard errors are shown.

FIG. 27. Total body weight gain in normal adult rats treated for 7 days with twice daily subcutaneous injections of excipient (solid bar), infusions of recombinant human insulin-like growth factor-1 (rhIGF-1, broad hatching), or the combinations of rhIGF-1 plus growth hormone releasing hormone (light shading), H w A W f K plus rhIGF-1 (narrow hatching), (inip) b b F-NH2 plus rhIGF-1 (open bar), (inip) b nmb bam plus rhIGF-1 (dark shading), or L-692,585 plus rhIGF-1 (horizontal lines). Weight gains tended to be greater after combination treatment. Means and standard errors are shown.

DETAILED DESCRIPTION OF THE INVENTION

A. Definitions

Terms used in the claims and specification are defined as set forth below unless otherwise specified.

The terms growth hormone releasing hormone (GHRH) or factor (GHRF/GRF) are used interchangeably and refer to the endogenous hypothalamic GH secretagogue, from any species, having the capability of binding to the pititutary somatotroph and inducing a rapid dose-dependent release of GH and biologically active analogs thereof. Included in this definition are; GHRH(1-44), GHRH(1-43), GHRH(1-40), and GHRH(1-29). Other examples of GHRH analogs are described in U.S. Pat. No. 4,622,312.

TABLE-US-00001 1 5 10 H-Tyr-Ala-Aap-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys- 15 16 20 Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln- 25 30 31 35 Asp-Ile-Met-Ser-Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln- 40 44 Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-NH2 Growth Hormone Releasing Hormone (GHRH)

The term somatostatin (SS) refers to the inhibitory hypothalamic tetradecapeptide capable of antagonizing in a dose-dependent manner the GH-releasing effect of GHRH. ##STR00036##

As used herein, "IGF-1" refers to insulin-like growth factor from any species, including bovine, ovine, porcine, equine, avian, and preferably human, in native-sequence or in variant form, and from any source, whether natural, synthetic, or recombinant. Preferred herein for animal use is that form of IGF-1 from the particular species being treated, such as porcine IGF-1 to treat pigs, ovine IGF-1 to treat sheep, bovine IGF-1 to treat cattle, etc. Preferred herein for human use is human native-sequence, mature IGF-1, more preferably without a N-terminal methionine, prepared, for example, by the process described in EP 230,869 published Aug. 5, 1987; EP 128,733 published Dec. 19, 1984