Effect of cromakalim on spontaneous activity of castrated rat vas deferens.
After castration rat vasa deferentia exhibited spontaneous activity. Cromakalim which acts by opening K+ channels has been shown to suppress this spontaneous activity following castration. Glibenclamide, a potent blocker of the ATP-sensitive K+ channels, inhibited this contrasting effect of cromakalim. The concentrations of cromakalim and glibenclamide that were employed are consistent with those active in different kinds of smooth muscle. The presented data are compatible with the hypothesis that castration decreases potassium conductance and that such an effect could be responsible for spontaneous activity.
Boselli
C
C
Istituto di Farmacologia, Facoltà di Farmacia, Università di Pavia, Italia.
Barbieri
A
A
Grana
E
E
D000818:Animals; D001578:Benzopyrans / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D019806:Cromakalim; D005905:Glyburide / Q000494:pharmacology; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D010276:Parasympatholytics / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011758:Pyrroles / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014649:Vas Deferens / Q000187:drug effects
D001578:Benzopyrans; D010276:Parasympatholytics; D011758:Pyrroles; D019806:Cromakalim; D005905:Glyburide; D009638:Norepinephrine