Effects of the vasoactive neuropeptides calcitonin gene-related peptide, substance P and vasoactive intestinal polypeptide on skin temperature in ovariectomized rats.

The effects of three vasoactive neuropeptides, calcitonin gene-related peptide (CGRP), substance P (SP) and vasoactive intestinal polypeptide (VIP), on vasodilation and skin temperature were investigated in ovariectomized (OVX) and sham-operated control rats. CGRP (0.01-1 nmol), VIP (0.01-10 nmol) and SP (0.1-100 nmol) produced vasodilation in PGF(2 alpha) (10 microM)-induced contraction of mesenteric vascular beds isolated from OVX and sham-operated rats in a dose-dependent manner. Intravenous injection of CGRP (1-10 microg/kg), VIP (10-50 microg/kg) and SP (10-50 microg/kg) elevated the skin temperature in OVX and sham-operated rats in a dose-dependent manner. CGRP had the greatest effect on both parameters, followed by VIP, with the smallest effect in SP. These parallel increases of vasodilation and skin temperature with CGRP were significantly greater in OVX rats than in sham-operated rats. However, no significant differences were observed in VIP- or SP-induced vasodilation and skin temperature increases between OVX and sham-operated rats. These results suggest not only that CGRP is closely related to the elevation of skin temperature but also that CGRP-induced responses are more affected by ovarian hormone deficiency.