Longitudinal studies of platelet cyclic AMP during healthy pregnancy and pregnancies at risk of pre-eclampsia.
1. Platelet behaviour in vitro in relation to cyclic AMP was studied longitudinally during pregnancy and in the same women when they were not pregnant. Subjects comprised a group of healthy primigravidae and a group of women deemed at risk of pre-eclampsia, on the basis of a previous history of the condition. 2. There was a progressive decline during pregnancy in sensitivity of platelets to inhibition of the arachidonic acid-induced release reaction by agents which act via cyclic AMP. This effect was maximum at 36 weeks' gestation. 3. Basal platelet cyclic AMP levels, and those in the presence of a phosphodiesterase inhibitor, did not change throughout the period of the study. 4. By contrast, platelet cyclic AMP accumulation in response to a variety of adenylate cyclase stimulators was reduced from early pregnancy, throughout the gestational period, compared with post-natally. This effect was noted when platelets were incubated with prostaglandins acting via different surface receptors or with forskolin and was most marked on co-incubation with a phosphodiesterase inhibitor. 5. Compared with healthy women, platelets from women with a previous history of pre-eclampsia tended to accumulate less cyclic AMP in response to adenylate cyclase stimulators. This was the case both during pregnancy and post-natally. Further investigation of adenylate cyclase activity in platelets in relation to pre-eclampsia is required.
Horn
E H
EH
Division of Therapeutics, University Hospital, Nottingham, U.K.
Cooper
J A
JA
Hardy
E
E
Heptinstall
S
S
Rubin
P C
PC
D000262:Adenylyl Cyclases / Q000097:blood; D000328:Adult; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000097:blood*; D005260:Female; D006801:Humans; D016285:Iloprost / Q000494:pharmacology; D008137:Longitudinal Studies; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy / Q000097:blood*; D018566:Pregnancy, High-Risk; D011446:Prospective Studies; D015230:Prostaglandin D2 / Q000494:pharmacology; D012307:Risk Factors; D012701:Serotonin / Q000097:blood; D013929:Thromboxane B2 / Q000097:blood
D016718:Arachidonic Acid; D012701:Serotonin; D013929:Thromboxane B2; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D016285:Iloprost; D015230:Prostaglandin D2