Platelet intracellular free calcium concentration in normotensive and hypertensive pregnancies in the human

1989 ◽  
Vol 76 (1) ◽  
pp. 67-71 ◽  
Author(s):  
S. M. Barr ◽  
K. R. Lees ◽  
L. Butters ◽  
A. O'Donnell ◽  
P. C. Rubin
Keyword(s):  
Platelet Activation ◽  
Calcium Concentration ◽  
Intracellular Free Calcium ◽  
Maximal Response ◽  
Free Calcium ◽  
Pregnancy Induced Hypertension ◽  
Third Trimester ◽  
Induced Hypertension ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration

1. Basal and stimulated platelet intracellular free calcium concentrations were measured in non-pregnant women and in third trimester patients who were either normotensive or who had pregnancy-induced hypertension or pre-eclampsia. There were 15 subjects in each group. 2. A trend for a reduction of the maximal response of platelet calcium levels to stimulation by 5-hydroxytryptamine was seen in pregnant groups compared with nonpregnant subjects, but this was significant only in pre-eclampsia. 3. No significant differences in basal or adenosine 5′-pyrophosphate-stimulated levels of platelet intracellular free calcium concentration were observed between the four groups. 4. These results illustrate that basal platelet calcium levels are unchanged in hypertension of pregnancy. Alterations in basal platelet calcium levels may not be involved in the platelet activation that is a feature of pre-eclampsia.

A cross-sectional study of basal platelet intracellular free calcium concentration in normotensive and hypertensive primigravid pregnancies

1990 ◽  
Vol 78 (1) ◽  
pp. 75-80 ◽  
Author(s):  
M. D. Kilby ◽  
F. Broughton Pipkin ◽  
S. Cockbill ◽  
S. Heptinstall ◽  
E. M. Symonds
Keyword(s):  
Calcium Concentration ◽  
Post Partum ◽  
Cross Sectional Study ◽  
Free Calcium ◽  
Sectional Study ◽  
Third Trimester ◽  
Cross Sectional ◽  
The Third ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration

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 < 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 preeclampsia). 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 < 0.02). However, no correlation could be demonstrated between [Ca2+]i and systemic blood pressure.

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