Fig. 6.

Medroxyprogesterone acetate inhibits E2 protection against ovariectomy-induced lipid peroxidation of brain mitochondria and whole-brain lipid fraction. Whole-brain mitochondria and whole-brain lipid fraction were isolated 24 h after in vivo exposure to E2 (30 μg/kg), MPA (120 μg/kg), E2+MPA (30 μg/kg + 120 μg/kg), or corn oil vehicle control (OVX). Ovary-intact (shamOVX) rats served as a positive control and were selected on the morning after the estrous cycle by vaginal cytology. Lipid peroxides in purified brain mitochondria (A) and brain lipid fraction (B) were measured using the leucomethylene blue assay. The bars represent mean ± sem from four animals per group. *, P < 0.05 compared with OVX (n = 4).