Calcitonin gene-related peptide (CGRP), acting via CGRP type 1 receptors, inhibits potassium-stimulated aldosterone secretion and enhances basal catecholamine secretion from rat adrenal gland.
Calcitonin gene-related peptide (CGRP) is a potent hypotensive peptide, that acts via two main subtypes of receptors, named CGRP1 and CGRP2. CGRP belongs to a regulatory-peptide family, that includes adrenomedullin (ADM) whose aldosterone antisecretagogue and catecholamine secretagogue actions are well demonstrated. Quantitative autoradiography showed the presence of [125I]CGRP binding sites in both rat adrenal zona glomerulosa (ZG) and medulla. Binding was displaced by the CGRP1-receptor antagonist CGRP(8-37), but not by the CGRP2-receptor agonist [cys(Et)2,7]-alphaCGRP (CGRP2-A). CGRP concentration-dependently inhibited 10 mM-stimulated (but not basal) aldosterone secretion from dispersed rat ZG cells, and enhanced basal catecholamine secretion from rat adrenomedullary fragments. The responses to the maximal effective concentration of CGRP (10-8 M) were blocked by 10-7 M CGRP(8-37). CGRP2-A (10-7 M) neither altered aldosterone response to 10 mM K+ nor enhanced basal catecholamine secretion. The conclusion is drawn that CGRP, like ADM, inhibits agonist-stimulated aldosterone secretion and stimulates basal catecholamine release in the rat, exclusively acting via CGRP1 receptors.
Tortorella
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Department of Human Anatomy and Physiology, Section of Anatomy, University of Padua, Via Gabelli 65, I-35121 Padua, Italy.
Macchi
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Forneris
M
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Nussdorfer
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GG
D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism; D053607:Adrenomedullin; D000450:Aldosterone / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive / Q000187:drug effects; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000502:physiology*
D002395:Catecholamines; D007457:Iodine Radioisotopes; D010446:Peptide Fragments; D010455:Peptides; D018015:Receptors, Calcitonin Gene-Related Peptide; C058636:calcitonin gene-related peptide (8-37); D053607:Adrenomedullin; D000450:Aldosterone; D015740:Calcitonin Gene-Related Peptide; D011188:Potassium