14102 studies
Cyclic gilts (96 +/- 1 kg) were used to determine the effect of active immunization against growth hormone-releasing factor GRF(1-29)-NH2 on concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Gilts were immunized against…
Glucocorticoids have been shown to inhibit GH secretion in normal man when administered in large amounts for several days. The aim of our study was 1. to investigate the acute effects of a single dose of glucocorticoids on GH secretion in normal man;…
The plasma GH levels of female rats during late pregnancy were determined using an automatic method for repetitive blood sampling from conscious animals. The plasma GH patterns were analysed by a pulse analysis computer program (PULSAR). The mean pla…
We have treated eight pre-pubertal children with partial GH insufficiency with continuous subcutaneous infusions of GHRH(1-29)NH2 at a dose of 60 ng/kg/min for periods of up to 1 year. In five children treated for 1 year, mean growth velocity increas…
The GH-releasing factor (GRF) analogue [His1,Nle27]-GRF(1-29) amide was used to study GRF receptor internalization in cultured rat anterior pituitary cells. The half-life of occupied receptors on the surface was approximately 10 min. Uptake of the an…
The guinea-pig is unusual in that it continues to grow at a normal rate after hypophysectomy. Although its pituitary gland appears to contain a GH, this has not been isolated or characterized, and nothing is known about its secretion or physiological…
Pituitary responsiveness to GHRH (1-29) NH2 (GHRH, 5 micrograms/kg iv) was analysed under sodium pentobarbital anesthesia (50 mg/kg ip), on days 30 and 90 in male rats orchidectomized or sham-operated 7 days earlier. Other groups of rats were orchide…
Obese patients are characterised by several neuroendocrine abnormalities, including characteristically a decrease in growth hormone responsiveness to GH-releasing hormone. In normal subjects, the GH response to GHRH is enhanced by the acetylcholinest…
Dynamic studies of growth hormone (GH) secretion were performed in two patients with ectopic GHRH syndrome. Patient 1 (female, 33 years old) had a growth hormone releasing hormone (GHRH) producing carcinoid of the lung with clinical features of acrom…
To determine the time onset of the growth hormone (GH) alteration in the genetically obese rat, we studied the in vivo and in vitro rat growth hormone releasing factor (rGRF(1-29)NH2)-induced GH secretion in 6- and 8-week-old lean and obese male Zuck…
Endogenous opioid peptides mediate the effect of suckling on LH and PRL in the domestic pig. However, the role of opioids in modulating GH during lactation in swine is not known. Primiparous sows that had been immunized against GRF(1-29) conjugated t…
In man, continuous infusion of GH-releasing hormone (GHRH) does not sustain GH secretion, unlike prolonged hypoglycemia. To further evaluate this difference in the stimulation of GH release we measured GH concentrations for 3 h during prolonged insul…
48 patients between one and seventeen years of age were stimulated with GRF (1-29) NH2. Seventeen of them showed a constitutional delay in growth and puberty, twenty-three suffered from growth-hormone deficiency (GHD) and eight had a suspected GHD as…
The role of vasoactive intestinal peptide (VIP), as a possible neurotransmitter of the intrinsic nerve plexus in the guinea pig gallbladder, was investigated by monitoring spontaneous contractile activity. VIP receptor antagonist (4 Cl-D-Phe6, Leu 17…
We evaluated six patients in whom a diagnosis of Sheehan's syndrome had been made. The plasma levels of the following hormones were measured: basal thyroxine (T4), estradiol and cortisol; and also follicle-stimulating hormone (FSH), luteinizing hormo…
Growth hormone inhibits its own secretion in animals and man but the mechanism for this inhibition is unclear: both stimulation of somatostatin release and inhibition of GH-releasing factor (GRF) release have been implicated. We have now studied the…
Previous peptide structure-activity investigations employing the psi[CH2NH] peptide bond isostere have produced antagonists when inserted into various sequences. These include bombesin, in which the incorporation of Leu13 psi[CH2NH]Leu14 produced a p…
We investigated the ability of two forms of Pituitary Adenylate Cyclase Activating Polypeptide [PACAP-38, the 38 amino acid peptide isolated from ovine hypothalamus, and PACAP-27, a shorter N-terminal (1-27) amidated version] to interact with specifi…
The effect of the vasoactive intestinal polypeptide (VIP) antagonist [N-Ac-Tyr1,D-Phe2]-GRF-(1-29)-NH2 on pelvic nerve-induced colonic vasodilation and VIP release was investigated in chloralose-anesthetized cats. VIP antagonist (10 and 50 nmol/kg in…
To study regulation of the secretion of human pituitary GH (hGH) and placental GH (hPGH) in the pregnant woman and human fetus, the GH-releasing factor Sermorelin [GRF-(1-29)-NH2] was administered to pregnant women at term (n = 5), just before electi…