Calcitonin gene-related peptide relaxed rat tail artery helical strips in vitro in an intracellular calcium-dependent manner.
The vasoactive properties of calcitonin gene-related peptide (CGRP) were examined using the helical strip of the rat tail artery as a model. CGRP was found to inhibit norepinephrine-induced contraction but not KCl- or vasopressin-induced contraction. No significant inhibition occurred in either KCl- or norepinephrine-stimulated strips when Ca2+ was added incrementally to otherwise Ca2+-free bathing solution. However, a dose-related inhibition to norepinephrine-stimulated contraction in Ca2+-free bathing solution was observed. This strongly suggests that CGRP exerts its effect by inhibiting the mobilization of intracellular Ca2+.
Kline
L
L
Department of Physiology, University of Alberta, Edmonton, Canada.
Pang
P
P
D000818:Animals; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009479:Neuropeptides / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014665:Vasodilator Agents / Q000494:pharmacology*
D009479:Neuropeptides; D014665:Vasodilator Agents; D011189:Potassium Chloride; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium; D009638:Norepinephrine