Effect of Estrogen to Antioxidant Enzymes in Rat Erythrocyte

Jeong, Soon In; Jung, Hyuk

Abstract

OBJECTIVE
To observe whether any relationship exists between the consentration of plasma estradiol (E2) and the plasma consentration of malondialdehyde (MDA) or whether a relationship exists between the consentration of plasma E2 and the activity of erythrocyte enzymes, superoxide dismutase (SOD) and catalase, in ovariectomized female rats.
METHODS
We used 40 ovariectomized Sprague-Dewley rats randomly assigned to four groups. The first group (group A) was allowed to evolve freely with no estrogen supply. A gel containing 17beta-estradiol was administered transdermally to the other three groups at dose of 5 micro gram/day (group B), 10 micro gram/day (group C) and 15 micro gram/day (group D). After 2 weeks of recovery date from operation and 4 weeks of estrogen treatment, blood samples were obtained from the four groups. The concentrations of plasma E2 and MDA and the concentrations of erythrocyte catalase and SOD were determined.
RESULTS
There were significant correlations between the plama E2 concentrations and the concentrations of erythrocytes catalase and SOD in the group C, D. Whereas catalase and SOD activities in erythrocytes was decreased in estrogen replacement group. Any relationship wasn't found between the E2 concentrations and the plasma MDA levels in all groups.
CONCLUSION
Thiese result suggested that the catalase and SOD in erythrocytes is related the plasma E2 concentration. This model may explain the contradictory findings presented by estrogens with respect to their pro-or antioxidant action. The further study will be needed to evaluate the effect of estrogen induced plasma lipid peroxidation.