Alterations of plasma calcium and intracellular and membrane calcium in erythrocytes of patients with pre-eclampsia.
BACKGROUND
Changes in plasma and intracellular calcium levels have been suggested in the pathogenesis of pre-eclampsia, however, membrane calcium content has not been studied so far. We compared intracellular and membrane calcium concentrations in erythrocytes of women with pre-eclampsia, healthy pregnant woman and controls to determine a possible alteration of membrane calcium in pre-eclampsia.


METHODS
Eighteen untreated, healthy pregnant woman and 16 pregnant nulliparous women with manifest pre-eclampsia were included, 25 healthy, age-matched woman served as controls. Atomic absorption spectroscopy was used for measurement of intracellular and membrane calcium content in erythrocytes and plasmalemmal preparations.


RESULTS
Plasma Ca++ concentrations were significantly lower in pre-eclamptic women (1.96 +/- 0.15 mmol/l, P < 0.01, mean +/- s.e.m.) compared to healthy controls (2.43 +/- 0.14 mmol/l) or women with uncomplicated pregnancies (2.20 +/- 0.10 mmol/l). Intracellular Ca++ concentrations were not different between groups, however, membrane Ca++ content was significantly increased in the pre-eclamptic patients (1.23 +/- 0.36 micromol/g membrane protein, P < 0.01) compared to control subjects (0.83 +/- 0.16 micromol/g) and healthy pregnant women (0.77 +/- 0.13 micromol/g).


CONCLUSIONS
Membrane calcium content is significantly increased in pre-eclamptic women despite low plasma Ca++ concentrations. This finding suggests an altered membrane ion transport and may be of importance for the pathogenesis of pre-eclampsia.
Kosch
M
M
Department of Internal Medicine D, University of Münster, D-48129 Germany.
Hausberg
M
M
Louwen
F
F
Barenbrock
M
M
Rahn
K H
KH
Kisters
K
K
D000328:Adult; D002118:Calcium / Q000097:blood*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D009994:Osmolar Concentration; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D012016:Reference Values
D002118:Calcium