A cross-sectional study of basal platelet intracellular free calcium concentration in normotensive and hypertensive primigravid pregnancies.
1. The intracellular free calcium concentration ([Ca2+]i) in washed human platelets was measured using the fluorescent indicator, fura-2, in a cross-sectional study of 36 normotensive, primigravid volunteers, 12 in each trimester of pregnancy and a further 12 at 6 weeks post partum. The results were compared with those obtained from 30 normal female volunteers not using oral contraception. 2. The mean basal [Ca2+]i in the platelets of the pregnant women in the first two trimesters (115.6 +/- 6.7 and 120.1 +/- 5.7 nmol/l, respectively) was not shown to differ significantly from that of normal non-pregnant volunteers (112.3 +/- 2.9 nmol/l). However, during the third trimester a significant increase in [Ca2+]i was noted (134.0 +/- 4.9 nmol/l; P less than 0.05), with a return to normal values in the post-partum period (108.2 +/- 6.1 nmol/l). 3. [Ca2+]i was also measured in the platelets of a group of 12 primigravid pregnant women in the third trimester whose pregnancies were complicated by gestational hypertension (pregnancy-induced hypertension and pre-eclampsia). A significant rise in basal [Ca2+]i was noted in the platelets of primigravidae whose pregnancies were complicated by pre-eclampsia (163.6 +/- 8.8 nmol/l) as compared with normotensive, third-trimester primigravidae (P less than 0.02). However, no correlation could be demonstrated between [Ca2+]i and systemic blood pressure.
Kilby
M D
MD
Department of Obstetrics and Gynaecology, University Hospital, Queens Medical Centre, Nottingham, U.K.
Broughton Pipkin
F
F
Cockbill
S
S
Heptinstall
S
S
Symonds
E M
EM
D000328:Adult; D001792:Blood Platelets / Q000737:chemistry*; D002118:Calcium / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood*; D010298:Parity; D011225:Pre-Eclampsia / Q000097:blood; D011247:Pregnancy / Q000097:blood*; D011249:Pregnancy Complications, Cardiovascular / Q000097:blood*; D012016:Reference Values
D002118:Calcium