Effects of plasma on the platelet antiaggregatory action of prostacyclin in pregnancy.
Platelet-poor plasma from 13 nonpregnant, 33 normally pregnant, and eight preeclamptic women was incubated with prostacyclin. The ability of platelet-poor plasma to diminish the antiaggregatory effect of prostacyclin was assessed by measuring this effect on arachidonic acid-induced platelet aggregation. Platelet aggregation greater than 95% in response to arachidonic acid was observed when incubated plasma without exogenous prostacyclin was assayed. When prostacyclin and platelet-poor plasma were preincubated together, subsequent arachidonic acid-induced platelet aggregation measured 9.6% in samples from nonpregnant patients, 40.3% in samples from normally pregnant patients, and 78.2% in samples from patients with preeclampsia. The ability of exogenous prostacyclin to inhibit arachidonic acid-induced platelet aggregation was significantly different in the presence of plasma from nonpregnant, normally pregnant, and preeclamptic women. These observations suggest that a plasma factor may affect the action of prostacyclin during pregnancy.
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D004347:Drug Interactions; D011464:Epoprostenol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood; D010949:Plasma / Q000502:physiology*; D010974:Platelet Aggregation / Q000187:drug effects*; D011225:Pre-Eclampsia / Q000097:blood; D011247:Pregnancy / Q000097:blood*; D011263:Pregnancy Trimester, Third
D001095:Arachidonic Acids; D016718:Arachidonic Acid; D011464:Epoprostenol