A synthetic analog of growth hormone-releasing hormone (GHRH 1-29) previously FDA-approved for diagnosing and treating growth hormone deficiency in children.
Vasoactive intestinal peptide (VIP) receptors coupled to activation of adenylate cyclase have been previously identified in seminal vesicle membranes of rat. In the present study we demonstrate that the synthetic peptides [4-Cl-D-Phe6,Leu17]VIP and t…
African Green monkeys were injected (2 x daily subcutaneously for six months) with human GRF(1-44)-NH2 (10 micrograms/kg BW) or a more potent analog, [desNH2Tyr1,Ala15]-hGRF(1-29)-NH2 (2 micrograms/kg BW) to determine the potential of each peptide to…
We used three putative vasoactive intestinal peptide (VIP) antagonists: 1) [4C1-D-Phe6,Leu17]VIP, 2) [N-Ac-Tyr1,D-Phe2] GRF(1-29)-NH2, and 3) VIP(10-28) to assess the involvement of endogenous VIP in the regulation of thyroid hormone secretion and th…
We evaluated the effects of iv pretreatment with exogenous GH on the GH response to GHRH either alone or in combination with pyridostigmine in 14 Type I diabetic patients and 6 normal subjects. All the subjects received an iv bolus injection of biosy…
A radioimmunoassay (RIA) for growth hormone-releasing hormone (GHRH) using a polyclonal antibody against synthetic GHRH(1-29)-Gly4-Cys-NH2 has been developed. The antiserum (RBM105) showed full cross-reactivity with GHRH-(1-44)NH2, GHRH-(1-40)OH, GHR…
The substance P(SP)/bombesin (Bn) antagonists [DArg1DTrp7,9Leu11] SP(P-7482), [DArg1-DPro2DTrp7,9Leu11]SP (P-7483), [DArg1DPhe5DTrp7,9Leu11]SP(P-7492), and the growth hormone releasing hormone (GHRH) antagonist [DArg2Ala8,9,15]GHRH(1-29)(DC21-366) we…
In a single-blind placebo-controlled study, the effect of an iv bolus injection of 100 micrograms GHRH(1-29)NH2 on the response to 200 micrograms TRH was assessed in 10 untreated patients with acromegaly to determine whether GHRH interacts with TRH i…
Possible antagonism between somatostatin (SS) and carp growth hormone-releasing factor (GRF) on growth hormone (GH) secretion was examined by radioimmunoassay in a dispersed rainbow trout pituitary cell culture system. SS (3 nM) significantly antagon…
Despite causing marked inhibition of somatic growth, glucocorticoids enhance both the response to GH-releasing hormone (GHRH) and the amplitude of naturally occurring GH secretory pulses in the male rat. The relative contribution of the two major hyp…
To study the possible involvement of hypothalamic growth hormone-releasing factor (GRF) in sleep regulation, a competitive GRF-antagonist, the peptide (N-Ac-Tyr1,D-Arg2)-GRF(1-29)-NH2, was intracerebroventricularly injected into rats (0.003, 0.3, and…
The influence of ovarian function on the pituitary responsiveness to growth hormone-releasing hormone (GHRH) was studied by measuring GH levels in serum before and after the injection of GHRH 1-29 NH2 (5 micrograms/kg i.v.) in female Wistar rats unde…
Using immunohistochemical methods, choline acetyltransferase and vasoactive intestinal polypeptide immunoreactive (ChAT-I and VIP-I) fine fibers with varicosity-like structures were observed in the rat and cat cerebral arteries. Acetylcholine (ACh) i…
A high density (in the pmol/mg protein range) of specific functional receptors for PACAP (pituitary adenylate cyclase activating polypeptide) was observed in membranes from rat brain cortex, olfactory bulb, hypothalamus, hippocampus, striatum, cerebe…
OBJECTIVE: The aim of this study was to investigate the effect of a single dose of clonidine on the pattern of GH release in response to a 10-hour continuous GRF infusion in normal man. DESIGN: Plasma GH was analysed in samples withdrawn at 20-minute…
The in vitro effect of synthetic human growth hormone-releasing hormone (GHRH) on mitogen-induced lymphocyte proliferation and lymphokine secretion was investigated. Peripheral blood mononuclear cells (PBMC) of healthy adults were incubated in the pr…
The aim of this study was to investigate the interrelationships between alpha 2-adrenergic and cholinergic pathways in the control of hypothalamic somatostatin (SRIF) secretion in humans. In eight normal volunteers subjects we compared the pattern of…
The hormonal responses of gestating sows to immunization against somatostatin conjugated to bovine serum albumin (SRIF-IMM) and/or injections of growth hormone-releasing factor (GRF) were studied with thirty-eight second parity sows. Immunization aga…
A striking sexual dimorphism exists in the pattern of GH secretion and rate of somatic growth; however, the mechanism(s) mediating this sex difference is unknown. To elucidate the physiological roles of the hypothalamic neuropeptides, somatostatin (S…
OBJECTIVE The aim of the study was to investigate whether pyridostigmine, a cholinesterase inhibitor which is thought to act at the hypothalamus to inhibit somatostatin secretion, would augment spontaneous or GHRH-stimulated serum GH levels in patien…
Growth hormone-releasing hormone (GHRH) increases serum GH levels in a dose-dependent manner. Pyridostigmine (PD), an acetylcholinesterase inhibitor, is able to elicit GH secretion when administered alone and to enhance the GH response to GHRH in nor…