Objective: The role of endogenous GHRH in arginine-, insulin-, clonidine- and l-dopa-induced GH secretion was studied in man using a GHRH antagonist (GHRH-Ant).
Design: Ten healthy adult males were studied for serum GH responses to arginine or insulin singly, or sequentially 120 min after GHRH injection with or without combined administration of GHRH-Ant. Further, GHRH, clonidine or l-dopa were sequentially administered to these subjects 120 min after the GHRH injection.
Results: The combined administration of GHRH-Ant distinctly inhibited the arginine- and insulin-induced GH release. When these four agents were sequentially administered 120 min after GHRH injection, the GH responses to clonidine and l-dopa disappeared completely while clear responses were observed to arginine and insulin administration. These responses to arginine and insulin were also completely inhibited by the combined administration of GHRH-Ant.
Conclusions: These results indicate that clonidine and l-dopa stimulate GH secretion mainly through the release of hypothalamic GHRH, and that arginine- and insulin-induced hypoglycaemia stimulate GH secretion mainly through the inhibition of hypothalamic somatostatin release. However, the presence of endogenous hypothalamic GHRH seems to be essential for the maximal stimulation of GH release induced by arginine and insulin.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1530/eje.0.1460197 | DOI Listing |
Drug Des Devel Ther
January 2025
Beijing Tongrentang Technology Development Co., Ltd. Pharmaceutical Factory, Beijing, 100079, People's Republic of China.
Purpose: This study aims to explore the mechanism of Yangxuerongjin pill (YXRJP) in the treatment of diabetic peripheral neuropathy (DPN) by network pharmacology and metabolomics technology combined with animal experiments, and to provide scientific basis for the treatment of DPN.
Methods: In this study, network pharmacology analysis was applied to identify the active compounds, core targets and signal pathways, which might be responsible for the effect of DPN. The DPN model was established by high-fat diet combined with streptozotocin (STZ) injection, and the rats were given administration for 12 weeks.
bioRxiv
January 2025
Ben-May Institute for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
Insulin degrading enzyme (IDE) is a dimeric 110 kDa M16A zinc metalloprotease that degrades amyloidogenic peptides diverse in shape and sequence, including insulin, amylin, and amyloid-β, to prevent toxic amyloid fibril formation. IDE has a hollow catalytic chamber formed by four homologous subdomains organized into two ~55 kDa N- and C- domains (IDE-N and IDE-C, respectively), in which peptides bind, unfold, and are repositioned for proteolysis. IDE is known to transition between a closed state, poised for catalysis, and an open state, able to release cleavage products and bind new substrate.
View Article and Find Full Text PDFCalcif Tissue Int
January 2025
Division of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Aeschenvorstadt 57, 4051, Basel, Switzerland.
Pentosidine (PEN), a surrogate marker of advanced glycation end-product formation, reflects increased non-enzymatic cross-linking in bone collagen, which is thought to be an important determinant of bone fragility in type 2 diabetes mellitus (T2DM). We aimed to investigate serum concentrations of PEN in patients with T2DM and controls without T2DM and to examine its relationship with bone parameters and metabolic state such as glycaemic control, insulin resistance and body weight. In a cross-sectional study-design, data from postmenopausal women and men with T2DM (n = 110) and controls without T2DM (n = 111) were evaluated.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Experimental and Clinical Physiology, Centre for Preclinical Research, Medical University of Warsaw, 02-097 Warsaw, Poland.
Numerous compounds involved in the regulation of the cardiovascular system are also engaged in the control of metabolism. This review gives a survey of literature showing that arginine vasopressin (AVP), which is an effective cardiovascular peptide, exerts several direct and indirect metabolic effects and may play the role of the link adjusting blood supply to metabolism of tissues. Secretion of AVP and activation of AVP receptors are regulated by changes in blood pressure and body fluid osmolality, hypoxia, hyperglycemia, oxidative stress, inflammation, and several metabolic hormones; moreover, AVP turnover is regulated by insulin.
View Article and Find Full Text PDFSci Rep
December 2024
Vocational School of Health Services, Atatürk University, Erzurum, Turkey.
Acute pancreatitis (AP) is a severe inflammatory condition affecting the pancreas, often leading to systemic inflammation and organ dysfunction. This study evaluated the effects of resveratrol (RES) and β-carotene (βC) on L-arginine-induced AP in rats. Forty-eight male Sprague Dawley rats were divided into six groups: Control (C), RES (20 mg/kg), βC (50 mg/kg), AP, AP + RES, and AP + βC.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!