Inhibitory effects of isradipine on spontaneous and oxytocin- and carbachol-stimulated contractions of rat myometrium.
Our aim was to investigate the effect of isradipine, a second-generation calcium channel blocker, on spontaneous and oxytocin- and carbachol-stimulated contractions of myometrium isolated from nonpregnant and pregnant rats. Amplitude, frequency, duration and integrated area of spontaneous and oxytocin- and carbachol-stimulated contractions of nonpregnant and pregnant rat myometrium were compared before and after the treatment with isradipine (10(-6) to 10(-4) mol/l). Isradipine inhibited contractions of myometrial strips isolated from nonpregnant and pregnant rats in a concentration-dependent manner, with a significant effect on the amplitude (10(-5) to 10(-4) mol/l) and integrated area (3 x 10(-6) to 10(-4) mol/l) of spontaneous and oxytocin- and carbachol-stimulated contractions. Isradipine induced similar concentration-dependent effects on the frequency and duration of spontaneous and carbachol-stimulated contractions at higher concentrations (3 x 10(-5) to 10(-4) mol/l) but had no effect on frequency and duration of oxytocin-stimulated contractions. Isradipine appears to be an effective relaxant in rat myometrium. This effect of isradipine may become therapeutically advantageous in clinical application for preterm labor.
Cetin
M
M
State Railway Hospital, Cumhuriyet University School of Medicine, Sivas, Turkey. cetin@turnet.net.tr
Kaya
T
T
Cetin
A
A
Sarioglu
Y
Y
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002217:Carbachol / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D017275:Isradipine / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009215:Myometrium / Q000187:drug effects*; D010121:Oxytocin / Q000494:pharmacology*; D010277:Parasympathomimetics / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats
D002121:Calcium Channel Blockers; D010277:Parasympathomimetics; D010121:Oxytocin; D002217:Carbachol; D017275:Isradipine