Effects of ovarian ischemia-reperfusion on luteal function in pregnant rats

An involvement of reactive oxygen species in CL regression has been reported. We have shown that a decrease in serum progesterone concentrations coincides with a decrease in superoxide dismutase (SOD) activities and an increase in lipid peroxide levels in the CL after Day 15 of pregnancy. Recently it has been found that ischemia-reperfusion stimulates reactive oxygen species production and causes tissue damage in various organs. We therefore tested the effect of ischemia-reperfusion in the ovary on CL function in pregnant rats. On Day 15 of pregnancy, after clamping of the bilateral ovarian vessels for 30 min, the ovaries were reperfused for 90 min by declamping. The ischemia-reperfusion decreased serum progesterone concentration and SOD activity in the CL and increased lipid peroxide in the CL 90 min after reperfusion. The effects of ischemia-reperfusion, including the decrease in serum progesterone concentrations, were completely blocked by simultaneous injection of SOD and catalase, but not by indomethacin administration. The present study shows that CL function was inhibited by reactive oxygen species produced by ischemia-reperfusion in the ovary and that the effect was not mediated through prostaglandins.