NITRIC-OXIDE AND SENSORY NERVES ARE INVOLVED IN THE VASODILATOR RESPONSE TO ACETYLCHOLINE BUT NOT CALCITONIN GENE-RELATED PEPTIDE IN RAT SKIN MICROVASCULATURE

Abstract

1. The contributions of sensory nerves and nitric oxide (NO) to vasodilator responses to acetylcholine (ACh) and calcitonin gene-related peptide (CGRP) were examined in rat skin microvasculature with a laser Doppler flowmeter to monitor relative blood flow. 2. Perfusion of ACh (100 microM; for 30 min) over a blister base on the rat hind footpad elicited microvascular vasodilatation and this response was not sustained. CGRP (1 microM; 10 min perfusion) also elicited vasodilatation and this response was maintained even when CGRP was no longer in contact with the blister base. 3. The vasodilator response to ACh was significantly smaller in rats pretreated as neonates with capsaicin to destroy p..