title: Inhibitory action of prostaglandin E1 on smooth muscle contraction and calcium responses.
abstract: The relation between the inhibitory action of prostaglandin (E1 (PGE1) and external Ca concentration was investigated using the guinea-pig isolated ureter and the perfused central artery of the rabbit isolated ear. PGE1 20 ng/ml reduced the ureteral contraction evoked by a single electrical stimulation. This inhibitory action of PGE1 was enhanced with a decreased external Ca concentration. PGE1 100 ng/ml also reduced Ca-induced contracture of the ureter depolarized in Ca-free K(80 mM)-Krebs' solution. Furthermore, PGE1 50 ng/ml inhibited the responses of peripheral vascular resistance to noradrenaline, and this effect increased with a reduced external Ca concentration.
mesh_terms: D000818:Animals; D001158:Arteries / Q000187:drug effects; D002118:Calcium / Q000037:antagonists & inhibitors*; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011458:Prostaglandins E / Q000494:pharmacology*; D011817:Rabbits; D014513:Ureter / Q000187:drug effects
chemical_list: D011458:Prostaglandins E; D002118:Calcium; D009638:Norepinephrine