NITRIC-OXIDE IS NOT INVOLVED IN THE EFFECTS INDUCED BY NONADRENERGIC NONCHOLINERGIC STIMULATION AND CALCITONIN-GENE-RELATED PEPTIDE IN THE RAT MESENTERIC VASCULAR BED
S. Amerini et al., NITRIC-OXIDE IS NOT INVOLVED IN THE EFFECTS INDUCED BY NONADRENERGIC NONCHOLINERGIC STIMULATION AND CALCITONIN-GENE-RELATED PEPTIDE IN THE RAT MESENTERIC VASCULAR BED, Neuropeptides, 25(1), 1993, pp. 51-56
The mechanism involved in the effects induced by the activation of per
ineural non-adrenergic non-cholinergic (NANC) nerves or by exogenous c
alcitonin gene-related peptide (CGRP) was investigated in the rat mese
nteric vascular bed (MVB) perfused with Kreb's solution containing met
hoxamine and guanethidine. The activation of NANC terminals of the tis
sue was carried out by means of electrical field stimulation (EFS). An
increase in the perfusion pressure of the preparations was observed i
n the presence of two inhibitors of nitric oxide synthase: N(G)-monome
thyl-L-arginine (L-NMMA) (100 muM) and N(G)-nitro-L-arginine methyl es
ter (L-NAME) (100 muM). However L-NMMA and L-NAME did not modify the r
elaxant effect induced by EFS and exogenous CGRP. Furthermore the rela
xant effect induced by EFS and exogenous CGRP was not affected by the
removal of endothelium from the preparations. These results provide ev
idence that the vasodilation induced by NANC stimulation or by exogeno
us CGRP in MVB does not involve NO production.