The effect of a calcium antagonist, nitrendipine, on the responses of isolated strips of human, chorionic plate artery to prostaglandins E2 and E1.
Six point concentration-response curves were established for the contractile effect of prostaglandin E2 (PGE2) on helically-cut strips of human chorionic plate arteries. Tissues were then allocated to one of four treatment groups: a control group and 3 groups exposed to the calcium channel blocker nitrendipine at 10(-9), 10(-7) or 10(-5) M. The concentration-response curves were then repeated. The addition of nitrendipine was associated with a significant depression of the induced contraction. The contractile response to the lower doses of PGE2 was replaced by a small relaxation in 63% of the treated tissues. It is suggested that in these tissues PGE2 exerts its constrictor effect via the receptor-operated channels and that nitrendipine is blocking this effect. Similar experiments performed with PGE1 showed great variability in the initial response. Nitrendipine 10(-5) M failed to exert any detectable effect on this response. Pregnancy-induced hypertension is associated with vasoconstriction in both the maternal and placental circulations. There also appears to be a relative excess of vasoconstrictor eicosanoid production. Nitrendipine may be of use in the treatment of this condition.
Broughton Pipkin
F
F
Chinnery
E
E
D000527:Alprostadil / Q000494:pharmacology*; D001158:Arteries / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002585:Cesarean Section; D002823:Chorion / Q000098:blood supply*; D015232:Dinoprostone; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009568:Nitrendipine; D011247:Pregnancy; D011458:Prostaglandins E / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011897:Random Allocation; D014661:Vasoconstriction / Q000187:drug effects*
D002121:Calcium Channel Blockers; D011458:Prostaglandins E; D009568:Nitrendipine; D000527:Alprostadil; D009543:Nifedipine; D015232:Dinoprostone