Effect of bethanechol chloride on rabbit bladder neck contractility: In-vitro study

Lee, Jeong Gu; Koh, Sung Kun

Abstract

Bethanechol promotes bladder emptying by acting on postganglionic parasympathetic effector cells within detrusor muscle to elicit a contraction and is widely used to enhance bladder emptying for incomplete lower motor neuron lesion, idiopathic hypotonic bladder end postoperative urinary retention. However its effects on bladder outlet is inconclusive. Therefore, in vitro study for the effects of bethanechol on the muscle strip from the rabbit bladder neck were undertaken. Ten male white rabbit bladders were divided into body, base and neck and contractile responses of three strips were done. Bethanechol chloride produces most potent contractile response on the bladder body and comparatively less on the bladder base and bladder neck in a dose-dependant manner. Maximal contractile pressures of bladder body and bladder neck were 6.29+/-0.72 and l.22+/-0.53gm tension respectively. Norepinephrine produce maximal contractile responses of 2.09+/-0.49gm tension on bladder body. 1.15+/-0.39 on bladder base and 2.6+/-0.55 on bladder neck. Contractile response or the bladder neck to bethanechol was 50% of those to norepinephrine. These results indicated that bethanechol produce contractile response on the rabbit bladder neck in some degree but weaker than those by norepinephrine.