Effect of edaravone on ischemia/reperfusion injury in rat urinary bladder--changes in smooth muscle cell phenotype and contractile function.

Edaravone is a newly developed radical scavenging agent that has been widely used for protection against ischemia/reperfusion (I/R) injury in patients with cerebral infarction. The present study investigated the effects of edaravone on the I/R injury in rat urinary bladder. Adult male rats were divided in the four groups: groups 1-3 received 1 hour of ischemia followed by 1 hour of reperfusion with saline and with edaravone (1 and 3 mg/kg body weight), and group 4 were age-matched control rats. The in vivo ischemia was created by clamping the vesical arteries for 1 hour and reperfusion was accomplished by removing the clips and lasted for 1 hour. Edaravone or saline were administered after reperfusion for 30 min. Following reperfusion, the bladder was excised and separated. Bladder smooth muscle cell (SMC) phenotypic expression was investigated in the electron microscope. The number of contractile and non-contractile bladder SMC phenotype according to the morphological criteria was counted and the ratio of non-contractile to contractile phenotype was calculated. The responses to electrical field stimulation and carbachol were recorded. Edaravone administration resulted in the protection of the morphological changes and contractile responses to both EFS and carbachol that were affected by the agent. Our findings demonstrate that edaravone has a potentially protective effect on I/R-induced damage in the rat bladder.