Prostacyclin-induced contraction of guinea-pig ileum: influence of drugs affecting calcium flux in the smooth muscle.
The contraction of guinea-pig terminal ileum induced by prostacyclin (PGI2) (20 nM) was inhibited by verapamil (0.01-1 microM) and by nifedipine (0.1-100 nM) in a concentration-dependent manner. Both drugs reduced the basal tone of the preparations only at the highest concentration tested. Papaverine (3-30 microM) reduced the basal tone as well as the PGI2-induced contractions at all the concentrations tested. The results show that extracellular calcium influx and possibly calcium mobilization from intracellular stores in smooth muscle cells are involved in the contractile response of the ileum to PGI2.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D011464:Epoprostenol / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D014700:Verapamil; D010208:Papaverine; D011464:Epoprostenol; D009543:Nifedipine; D002118:Calcium