Methysergide, a clinically-used blocker of serotonin receptors, was administered to 10 normal young men at a dose of 2 mg every 6 h for 48 h. After drug treatment, serum levels of growth hormone during sleep were 41.9% higher than placebo values (less than 0.001). In contrast, drug treatment was associated with a 36.4% decrease in stimulated growth hormone secretion during insulin tolerance testing (P less than 0.01). These opposite effects of methysergide suggest that different mechanisms are responsible for sleep-related and insulin-induced growth hormone secretion. Accordingly, data obtained with pharmacologic stimuli may lead to erroneous inferences regarding physiologic growth hormone control mechanisms. Administration of methysergide profoundly suppressed sleep-related prolactin secretion; overall nocturnal mean prolactin fell by 70.3% from 4.30+/-0.19 to 1.28+/-0.06 ng/ml (P less than 0.0001). It appears that serotonin may be significant modulating neurotransmitter for the control of growth hormone secretion, limiting sleep-related release, and enhancing insulin-induced release. It seems likely from these data that the role of serotonin in the control of prolactin secretion is relatively more important, since serotonin receptor blockade dramatically reduced sleep-related prolactin secretion.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC301917PMC
http://dx.doi.org/10.1172/JCI108139DOI Listing

Publication Analysis

Top Keywords

growth hormone
24
prolactin secretion
16
hormone secretion
16
sleep-related prolactin
12
secretion
8
drug treatment
8
growth
6
hormone
6
prolactin
5
sleep-related
5

Similar Publications

Background: Space-induced plant mutagenesis, driven by cosmic radiation, offers a promising approach for the selective breeding of new plant varieties. By leveraging the unique environment of outer space, we successfully induced mutagenesis in 'Deqin' alfalfa and obtained a fast-growing mutant. However, the molecular mechanisms underlying its rapid growth remain poorly unexplored.

View Article and Find Full Text PDF

Herbicide paraquat dichloride, a potent redox agent found its way to natural water bodies and influences their health; however, its impact on the reproductive health of fish is potentially less studied and requires clear investigation. This study was conducted to elucidate its effect on the gonadal health of female fish, Channa punctatus over 60 days. The 96-h LC of test herbicide was calculated as 0.

View Article and Find Full Text PDF

The sequence-structure-function relationship of intrinsic ERα disorder.

Nature

January 2025

Case Comprehensive Cancer Center and Department of Nutrition, Case Western Reserve University School of Medicine, Cleveland, OH, USA.

The oestrogen receptor (ER or ERα), a nuclear hormone receptor that drives most breast cancer, is commonly activated by phosphorylation at serine 118 within its intrinsically disordered N-terminal transactivation domain. Although this modification enables oestrogen-independent ER function, its mechanism has remained unclear despite ongoing clinical trials of kinase inhibitors targeting this region. By integration of small-angle X-ray scattering and nuclear magnetic resonance spectroscopy with functional studies, we show that serine 118 phosphorylation triggers an unexpected expansion of the disordered domain and disrupts specific hydrophobic clustering between two aromatic-rich regions.

View Article and Find Full Text PDF

Ghrelin enhances feeding by activating the growth hormone secretagogue receptor (GHSR). In the brain, GHSRs are expressed in regions responsible for regulating food motivation including the ventral tegmental area (VTA). Endogenous cannabinoids also promote food seeking behaviors through the cannabinoid receptor 1 type (CB-1Rs) in brain regions including the VTA.

View Article and Find Full Text PDF

Adult growth hormone deficiency (AGHD) is often accompanied with metabolic dysfunction-associated steatotic liver disease (MASLD). Although some studies reported that MASLD is ameliorated by growth hormone replacement therapy (GHRT), the characteristics of AGHD that are associated with an improvement of hepatic steatosis by GHRT remain unknown. We aimed to investigate whether GHRT affects hepatic lipid accumulation as well as biochemical parameters, and investigated the association between these parameters (UMIN000044989).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!