Effects of Ischemia on the function of the isolated rat detrusor muscle.

Ischemia of vital organs causes various degrees of impairment. We studied the in vitro effects of ischemia on the function of the rat bladder. Ischemia was induced by ligation of the bilateral (bilateral ischemia) or right (unilateral ischemia) internal iliac arteries. Bladder weight increased significantly following 1 week of bilateral and unilateral ischemia. Passive tension was significantly higher in ischemic bladders than in control bladders at an increase in length between 6 and 12 mm. In both control and ischemic bladders, active tension was highest at a 16-mm increase in length. Bladders subjected to unilateral or bilateral ischemia for 1 or 2 weeks demonstrated impaired contractile responses to field stimulation, bethanechol, ATP and KCl. There were no differences in contractile strength between muscle specimens obtained from the ipsilateral or contralateral sides of unilateral ischemic bladders. Our findings showed that unilateral and bilateral ischemia inhibited the in vitro contractile strength of the detrusor muscle in response to intramural and pharmacologic stimulation.