Cjm. Degroot et al., PLASMA FROM PREECLAMPTIC WOMEN INCREASES HUMAN ENDOTHELIAL-CELL PROSTACYCLIN PRODUCTION WITHOUT CHANGES IN CELLULAR ENZYME-ACTIVITY OR MASS, American journal of obstetrics and gynecology, 172(3), 1995, pp. 976-985
OBJECTIVE: We investigated differences in prostacyclin production by e
ndothelial cells exposed to plasma from either preeclamptic women or n
ormal pregnant women. STUDY DESIGN: A case-control study of matched pr
eeclamptic and normal pregnancies was used to compare prostacyclin syn
thesis by human umbilical vein endothelial cells incubated with pregna
ncy plasma for 24 hours. Prostacyclin concentrations in conditioned me
dia were measured by radioimmunoassay of its stable metabolite (6-keto
-prostaglandin F-1 alpha). Human umbilical Vein endothelial cell lysat
es were used to determine concentrations of the enzymes cyclooxygenase
and prostacyclin synthase. RESULTS: Prostacyclin production by human
umbilical Vein endothelial cells incubated with plasma from preeclampt
ic women was significantly greater than that by cells exposed to norma
l pregnancy plasma. Differences In prostacyclin production under the t
wo experimental conditions could be explained neither by differences i
n enzyme mass nor activities of cyclooxygenase and prostacyclin syntha
se. CONCLUSION: The stimulatory effect of preeclampsia plasma on prost
acyclin biosynthesis in human umbilical vein endothelial cells appears
to be manifested at a step(s) proximal to the activation of cyclooxyg
enase. Possible mechanisms are increased phospholipase A(2), lipoprote
in, or lipid peroxide activities in preeclampsia.