This study investigated whether production of
reactive oxygen species by neutrophils differs between women with
preeclampsia and those with
essential hypertension. First, we assessed
superoxide production by neutrophils during pregnancy and 4 weeks after delivery in 15 healthy pregnant women, 12 women with
preeclampsia, and 7 pregnant women with
essential hypertension. We then examined effects of serum from each subject on
superoxide production by neutrophils obtained from healthy nonpregnant women. Neutrophil
superoxide production was measured by
cytochrome C reduction.
N-formyl-methionyl-leucyl-phenylalanine-stimulated
superoxide production was significantly increased in neutrophils from women with
preeclampsia and women with
essential hypertension compared with normal pregnant women. Four weeks postpartum, the level of
superoxide production was significantly decreased in women with
preeclampsia but not in women with either normal pregnancy or
essential hypertension. When neutrophils obtained from nonpregnant women were preincubated with predelivery sera from each group, sera from women with
preeclampsia significantly enhanced
superoxide production compared with sera from the other 2 groups. When postpartum serum was used, enhancement of neutrophil
superoxide production by serum from women with
preeclampsia was significantly decreased compared with that by predelivery serum. In conclusion, increased neutrophil
superoxide production resolved after delivery in
preeclampsia, whereas activation persisted postpartum in women with
essential hypertension. The different transition of neutrophil
superoxide production in response to pregnancy appears to be that
preeclampsia is characterized by the presence of serum factors that enhance neutrophil
superoxide production. Thus, in
preeclampsia, serum factors bear a more essential role producing
superoxide than a behavior of neutrophils.