A possible effect of sulfhydryl reagents on the contractile activity of the rat detrusor muscle

Resim S., Buyuknacar H., Gocmen C., Onder S., Dikmen A.

EUROPEAN JOURNAL OF PHARMACOLOGY, vol.442, no.3, pp.295-299, 2002 (SCI-Expanded) identifier identifier identifier


We aimed to investigate the effect of sulthydryl (SH) inactivating agents, ethacrynic acid and N-ethylmaleimide, on the contractile activity of rat detrusor muscle. Wistar Kyoto rats weighing 150-250 g were anaesthetized with ketamine and bled to death, The urinary bladders were surgically removed and detrusor strips were mounted under 0.5 g tension in organ baths. The responses were recorded with isotonic transducers on polygraph paper, After an equilibrium period. the tissues were contracted by electrical field stimulation, acetylcholine, ethacrynic acid or N-ethylmaleimide and the effects of L-Cysteine, glutathione, verapamil, Ca2+-free solution, sodium nitroprusside or atropine were then examined on these contractions. Verapamil. Ca2+-free solution or atropine significantly reduced the contractions elicited by electrical field stimulation and acetylcholine whereas L-cysteine, glutathione or sodium nitroprusside had no effect on the contractions in response to these Stimuli, L-Cysteine, glutathione, verapamil or Ca2+-free solution significantly inhibited the contractions induced by ethacrynic acid or N-ethylmaleimide. Sodium nitroprusside slightly inhibited only the contraction induced by ethacrynic acid but not that with N-ethylmaleimide, Atropine has no action on the contractions in response to these SH reagents. These findings suggest that SH reagents may play a role in the contractile activity of rat detrusor muscle and this action seems to be related to the gating of Ca2+ channels, Further experiments are needed to determine the cellular mechanism(s) of action by which these SH reagents act on the detrusor smooth muscle. (C) 2002 Elsevier Science B.V. All rights reserved.