RESUMEN
OBJECTIVE: Our purpose was to investigate urinary malondialdehyde (MDA), manganese superoxide dismutase (Mn-SOD) activity and polymorphism in placental tissues of women with preeclampsia and to evaluate oxidative stress in the pathophysiology of preeclampsia. METHODS: Urins and placental tissues were obtained from 20 normal and 20 preeclamptic women at 3rd trimester. Urinary MDA was assayed by an high performanance liquid chromatography (HPLC). The placental Mn-SOD activity was assayed by westen blotting and The placental Mn-SOD genotyping was assayed by PCR-RFLP. Data were analyzed statistically using Student's t-test and Chi-square test. RESULTS: 1) Urinary concentration of MDA was not significantly different in preeclampsia (4.43+/-2.37 ug/g) as compared with normotensive pregnancy (4.39+/-1.17 ug/g). 2) Preeclamptic women had similar Mn-SOD activity in placenta (1.04+/-0.04U/mL protein) as compared with normotensive pregnancy (1.44+/-0.34 U/mL protein). 3) No significant difference in the polymorphismthe of Mn-SOD genotype in placenta was observed between preeclampsia and normotensive pregnancy (X2=0.06, p>0.05) CONCLUSION: The findings in this study do not show that oxidative stress might be a pathogenetically relevent process causally contributing to the disease, and polymorphism in the Mn-SOD genotype in placenta do not seem to be risk factors for preeclampsia.