NAD(P)H oxidase associated superoxide production in human placenta from normotensive and pre-eclamptic women

Oxidative stress plays an important role in the development of pre-eclampsia. Recently, the superoxide producing enzyme NAD(P)H oxidase was shown to be present in placental trophoblast. In this pilot-study we investigated the NAD(P)H oxidase associated superoxide production as modulator of placental oxidative stress in normotensive pregnancy (n = 19; gestational age 38(+6)+/-0(+1)weeks(+days)) and pre-eclampsia (n = 15; gestational age 34(+3)+/-1(+5)weeks(+days)) using a lucigenin assay. Specificity of superoxide generation by NAD(P)H oxidase was assessed using the inhibitors L-NAME, rotenone, allopurinol, DPI and TIRON. Superoxide production was measurable in all placenta tissues and was inhibited by DPI and TIRON. No significant differences for total superoxide production (O2*total), maximal superoxide production (O2*max), or the rate of superoxide production were found between normotensive and pre-eclamptic women. However, women with early onset of disease had a higher O2*total as compared to those with a late onset disease. We conclude that human placenta contains a functional NAD(P)H oxidase that is highly active, which could be an important source of superoxide during pregnancy and pre-eclampsia. These data justify more detailed investigation of the role of NAD(P)H oxidase and placental oxidative stress in complicated pregnancies.