The myotropic and plasma-calcium modulating effects of calcitonin gene-related peptide (CGRP).
Human and rat calcitonin gene-related peptides cause a dose-related contraction of guinea pig ileum, which is antagonised by an anti-histamine, mepyramine, and an anticholinergic compound, hyoscine. Both peptides also cause a positive inotropic and a positive chronotropic effect in the rat isolated auricle and these responses are antagonised by propranolol, a B adrenoceptor blocker. Further, the peptides lower plasma calcium levels in both rats and rabbits in a dose-related manner resembling calcitonin; in the rabbit, but not in the rat, the initial calcium lowering effect is succeeded by hypercalcaemia at higher doses, while in the chick, only the parathyroid hormone-like calcium-raising effect is seen.
D000818:Animals; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium / Q000097:blood*; D002645:Chickens; D006168:Guinea Pigs; D006325:Heart Atria; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007082:Ileum / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects*; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D013045:Species Specificity
D009419:Nerve Tissue Proteins; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium