Increased Prooxidative Activity Stimulating the Oxidative Modification of Proteins in the Umbilical Venous Plasma and Placenta of Preeclampsia

Kim, Eun Mi; Kim, Yoon Ha; Ahn, Bong Whan; Yang, Sung Yeul; Kim, Cheol Hong; Cho, Moon Kyoung; Kim, Seok Mo; Song, Tae Bok

Abstract

OBJECTIVE
This study was performed to compare the prooxidative activity stimulating the protein carbonyl formation by cephalosporins in the umbilical venous and placenta of preeclampsia with that of normal pregnancy.
METHODS
Lipid peroxide levels in the umbilical venous plasma and placental tissue homogenates of normal pregnancy (n=12) and preeclampsia (n=12) were measured by thiobarbituric acid reaction. The basal protein carbonyl contents in the umbilical venous plasma and placental tissue homogenates of normal pregnancy (n=12) and preeclampsia (n=12) were determined by the 2,4-dinitrophenylhydrazine (DNPH) method. After samples of them were mixed and incubated up to 5 hours with 0.2 mL of 1 mM moxalactam or cephalothin, the protein carbonyl contents in them were measured by DNPH.
RESULTS
Protein carbonyls formation by moxalactam and cephalothin in the umbilical venous plasma and of women with preeclampsia were significantly higher than that of women with normal pregnancy (8.5+/-2.0 vs. 6.6+/-1.4 nmol/mg protein, p<0.05, 7.6+/-1.6 vs. 6.2+/-1.2 nmol/mg protein, p<0.05). Protein carbonyls formation by moxalactam and cephalothin in the placental tissue homogenates of women with preeclampsia were significantly higher than that of women with normal pregnancy (17.6+/-5.3 vs. 13.0+/-4.2 nmol/mg protein, p<0.05, 16.1+/-5.2 vs. 12.5+/-4.4 nmol/mg protein, p<0.05). There were significant positive correlations between lipid peroxide and cephalosporins induced protein carbonyls levels of umbilical venous plasma, and placental tissue homogenates (p<0.01).
CONCLUSION
These results suggest that increase in the prooxidative activity stimulating the oxidative modification of proteins in placenta may be involved in the pathogenesis of preecalmpsia.