48 The role of transmembrane redox system of erythrocytes in hypertension: From fetuses to pregnancy-induced hypertension

Abstract

Introduction Several studies in preeclampsia have shown evidence for the existence of pro-oxidative state, whose starting point at placental level, would arise from maternal and fetal immunogenetic predisposition factors, accompanied of microangiopathic hemolysis. Transmembrane reductase (TMR) is an NAD(P)H dependent enzyme present in endothelial cells and erythrocytes with antioxidant and anti-apoptotic properties. This system is altered in hypertension and in several other pathological situations associated to low-grade inflammation. Objectives To evaluate if TMR activity is related to preeclampsia and if this may affect fetuses. Methods In one cohort, we studied TMR activity in erythrocytes in 85 pregnant women with 27.1 ± 6.6 years old, being 47 (55.3%) preeclamptic (PE) and 38 (44.7%) normotensive (NT)-pregnant women. In other cohort, we also evaluate TMR activity in erythrocytes, in the following groups of pregnant women (mean gestational age of 37 weeks) and some fetuses of this group: n = 67 PE, n = 93 NT-pregnant, n = 57 fetuses of NT-pregnant women and n = 16 fetuses of PE women. TMR activity (mmol/L cell/h) was determined in erythrocytes of pregnant women and umbilical cord by a spectrophotometric method. For statistical analysis Student t -test and binary regression logistic were used. P Results TMR activity was significantly lower in PE women in relation to NT-pregnant women (4.21 ± 0.33 versus 5.97 ± 0.41, P = 0.001). Since TMR activity varies with age, when adjusted the levels of TMR for age, we observed that TMR activity maintains its protective effects (OR = 0.74, 95% CI 0.58–0.96, P = 0.021). From another cohort, TMR activity was lower in PE women comparing with NT-pregnant women (4.5 ± 2.2 versus 5.5 ± 3.2). The TMR activity was higher in umbilical cord, being lower in fetuses of PE women comparing with fetuses of NT-pregnant (5.7 ± 2.2 versus 7.2 ± 3.8). In relation to mothers, TMR of fetuses of PE women was greater than their mothers (5.7 ± 2.2 versus 4.5 ± 2.2). Conclusions TMR activity is lower in preeclampsia, which may have repercussions in their fetuses.