The immediate effect of nitric oxide on the rabbit bladder after ovariectomy

Ovariectomy resulted in decreased blood flow and hypoxia to the bladder mucosa and smooth muscle. Nitric oxide (NO) played an important role in regulating bladder function during bladder ischemia and reperfusion. This study was designed to evaluate the role of NO on bladder function in the first few days after ovariectomy. Female rabbits were separated into three groups, one which received no medication, pre-medicated with N(omega) -nitro-L-arginine methyl ester (L-NAME) and the third treated with L-arginine. Non-ovariectomized controls and at 1 and 3 days post-ovariectomy, animals from each group were euthanized. Cystometry and in vitro isometric contractile responses were recorded and the oxidative stress markers, nitrotyrosine and protein carbonylation were determined. L-NAME treatment did not significantly alter bladder function after ovariectomy. L-arginine fed, ovariectomized rabbits had lower intravesical pressure and better contractile responses to all forms of stimulation than the ovariectomized rabbits with or without L-NAME. Furthermore, the ovariectomized ones with or without L-NAME had higher oxidative stress markers than L-arginine fed rabbits. This study clearly demonstrates that feeding rabbits with L-arginine can protect the bladder from oxidative free radical damage following short term ovariectomy.