The Rho-kinase inhibitor Y-27632 and the soluble guanylyl cyclase activator BAY41-2272 relax rabbit vaginal wall and clitoral corpus cavernosum

The effects of Y-27632, a Rho-kinase inhibitor and BAY41-2272, a soluble guanylyl cyclase activator, on the tone and nitrergic responses of rabbit vaginal wall and clitoral corpus cavernosum were investigated. Y-27632 and BAY41-2272 (10nM-10muM) elicited concentration-dependent relaxation of phenylephrine-induced tone in both tissues. IC(50) values of Y-27632 for vaginal and clitoral tissues were 370 +/- 30 nM, and 467 +/- 14 nM, respectively. BAY41-2272 had IC50 values of 478 54 nM and 304 +/- 38 nM respectively. The effect of the Y-27632 on the tissue tone was not affected by an inhibitor of nitric oxide synthase (L-NAME; 500 muM). However, L-NAME reduced the potency of BAY41-2272 in the clitoral corpus cavernosum but not in the vaginal wall. BAY41-2272 enhanced nitrergic relaxation responses only in the clitoral corpus cavernosum. Y-27632 had no effect on nitrergic relaxations in either tissue. These results demonstrate that Y-27632 and BAY41-2272 elicit relaxation of the rabbit vaginal wall and clitoral corpus cavernosum.