A possible effect of sulfhydryl reagents on the contractile activity of the rat detrusor muscle.
We aimed to investigate the effect of sulfhydryl (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, Ca(2+)-free solution, sodium nitroprusside or atropine were then examined on these contractions. Verapamil, Ca(2+)-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 Ca(2+)-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 Ca(2+) channels. Further experiments are needed to determine the cellular mechanism(s) of action by which these SH reagents act on the detrusor smooth muscle.
Resim
Sefa
S
Department of Urology, Medical Faculty, Sütcü Imam University, Kahramanmaraş, Turkey.
Büyüknacar
H Sinem Göktürk
HS
Göçmen
Cemil
C
Onder
Serpil
S
Dikmen
Atilla
A
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D003545:Cysteine / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004976:Ethacrynic Acid / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D051381:Rats; D011921:Rats, Inbred WKY; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D001743:Urinary Bladder / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D004232:Diuretics; D013439:Sulfhydryl Reagents; D014665:Vasodilator Agents; D014700:Verapamil; D005978:Glutathione; D003545:Cysteine; D004976:Ethacrynic Acid; D000109:Acetylcholine; D005033:Ethylmaleimide