Effect of Ethanol on the Contractility of the Muscle Strips of the Bladder Neck in the Rabbit / 대한비뇨기과학회지

ABSTRACT

PURPOSE: Ethanol is known to induce bladder neck contraction so that it may cause acute urinary retention in patients with benign prostatic hyperplasia. We investigated whether ethanol has a-sympathomimetic effects in the bladder neck. MATERIALS AND METHODS: 36 New Zealand rabbits weighing from 2.5-3.0kg were used for this experiment. The rabbits were sacrificed by air embolism and the urinary bladder was immediately removed. The urinary bladder was dissected free from surrounding tissues and divided into the bladder body and neck in oxygenated Tyrode's solution. The bladder neck muscle strips were taken and the contractile responses to electrical field stimulation(2, 4, 8, 16 and 32Hz) and phenylephrine(1 mM), adenosine triphosphate(ATP, 100mM) and KCI(100mM)were measured. RESULTS: The frequency-response curve by electrical stimulation in ethanol pretreated Tyrode's solution were attenuated, but tonic contractions were not affected. ATP induced contraction was also attenuated. Ethanol showed relaxing effects in the contractile responses elicited by phenylephrine and KCI. CONCLUSIONS: From these studies, ethanol is shown to exert direct inhibitory action on bladder neck contraction presumably by lowering the calcium sensitivity of the smooth muscle in the rabbit.