Effects of estrogens and androgens on erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase activities during the menstrual cycle

The effects of physiological changes in estrogens and androgens on the eryt hrocyte antioxidant superoxide dismutase, catalase and glutathione peroxida se enzyme activities during the menstrual cycle were investigated in health y eumenorrheic women. Blood samples were taken on alternate days from twelv e normally cyclic women (age range: 20 to 27 years; mean age: 24.1 years) f rom the first day of one menstrual cycle until the first day of the subsequ ent one. Plasma was analyzed for FSH, LH, estradiol, progesterone, testoste rone, free testosterone and androstenedione concentrations. Erythrocyte sup eroxide dismutase, catalase and glutathione peroxidase activities were eval uated on the same days and cycle length was standardized on the basis of th e preovulatory estradiol peak. Significant cyclic phase-related changes wer e observed in glutathione peroxidase (P<0.05), with higher glutathione pero xidase activity levels from the late follicular to the early luteal phase c ompared with those found in the early follicular phase (P<0.001 and P<0.002 respectively). A significant positive correlation was observed between mea n estradiol and glutathione peroxidase cycle-related variations (r=0.80, P< 0.001), whereas no significant cycle phase-dependent changes were seen in s uperoxide dismutase and catalase. No effect of progesterone and androgens o n the erythrocyte antioxidant enzyme system was documented. The findings in dicate that physiological ovarian estradiol production during the menstrual cycle may have an important role in regulating erythrocyte glutathione per oxidase activity.