Increased Skin Flap Survival and Arterial Dilation by Calcitonin Gene-Related Peptide: A Study in the Pig

Abstract

Calcitonin gene-related peptide (CGRP), a recently discovered neuropeptide, is a potent vasodilator and increases blood flow in many vascular beds. The effect of CGRP treatment was investigated in critical pig pedicle and island flaps. Prior to pharmacological treatment the peroperative circulation border was estimated with fluorescein. Intradermal or intraarterial flap treatment with CGRP was given. Control flaps were untreated or injected with saline. Increased or decreased survival was calculated as the difference between the peroperative fluorescein penetration border and the survival border one week after surgery. CGRP treatment significantly increased the survival of both random pedicle and island flaps. CGRP doses as low as 3 ml x 10(-14) M (equal to 0.03 fmoles) increased the survival of random pedicle flaps. In 4 untreated pigs the deep circumflex iliac arteries were excised and artery ring preparations were studied in vitro. A dose-dependent relaxation of artery rings was noted between 10(-9) M and 10(-7) M CGRP.