Neutrophil platelet-activating factor in normal and hypertensive pregnancy and in pregnancy-induced hypertension.
1. Platelet-activating factor is a phospholipid with potent vasodilator and platelet-activating properties. To test the hypothesis that a generalized change in cellular platelet-activating factor metabolism may be involved in the systemic vasodilatation of normal pregnancy or pregnancy-induced hypertension, we studied platelet-activating factor and eicosanoid synthesis in isolated leucocytes obtained from pregnant women before and after delivery compared with age-matched non-pregnant control subjects. Parallel observations were carried out in age- and gestation-matched women with uncomplicated hypertension in pregnancy and in women with pregnancy-induced hypertension and a further set of normotensive pregnant control subjects. 2. Leucocyte counts were higher in all pregnant groups compared with non-pregnant control subjects. Neutrophil production of platelet-activating factor and metabolites of prostacyclin, prostaglandin E2 and thromboxane in response to calcium ionophore stimulation were all lower in pregnant women compared with non-pregnant control subjects, but returned to similar levels 6 weeks post partum. There was no significant difference between essential hypertensive and normotensive groups. When women with pregnancy-induced hypertension were a priori sub-divided into those with or without proteinuria, subjects with proteinuria showed significantly lower levels of neutrophil platelet-activating factor synthesis. 3. Plasma levels of the platelet-activating factor metabolite (lyso-platelet-activating factor) were also lower in pregnancy, suggesting alterations in the activity of enzymes controlling synthesis or degradation of this phospholipid in pregnancy. In pregnancy-induced hypertension the levels of plasma lyso-platelet-activating factor were higher than in normal pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)
Beilin
L J
LJ
Department of Medicine, University of Western Australia, Perth.
Croft
K D
KD
Michael
C A
CA
Ritchie
J
J
Schmidt
L
L
Vandongen
R
R
Walters
B N
BN
D000328:Adult; D015777:Eicosanoids / Q000097:blood; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000209:etiology; D009504:Neutrophils / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000378:metabolism*; D011247:Pregnancy / Q000097:blood*; D011249:Pregnancy Complications, Cardiovascular / Q000097:blood*
D015777:Eicosanoids; C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor