The superoxide generation of neutrophils in normal and preeclamptic pregnancies.

Abstract

To determine whether preeclampsia enhances superoxide generation of neutrophils. Samples were obtained from 12 normal nonpregnant, 15 normal pregnant, and 11 preeclamptic women. The superoxide production of neutrophils was measured by the superoxide dismutase-inhibitable reduction of ferricytochrome C at 550-540 nm using a dual-wavelength spectrophotometer. N-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced superoxide production of neutrophils was significantly higher in preeclamptics than in normal nonpregnant and pregnant subjects, whereas phorbol 12-myristate 13-acetate-induced superoxide production did not differ among them. When neutrophils prepared from normal nonpregnant women were preincubated with sera from the study groups, sera from preeclamptics enhanced the FMLP-induced superoxide production to about twice that of the other subjects. The serum-enhancing factor appeared to be a heat-labile protein, different from other known activators. Preeclampsia is characterized by the presence of a neutrophil activator that enhances superoxide production. This enhanced production may contribute to the pathophysiologic changes observed in preeclampsia.