抄録
Copper/zinc superoxide dismutase (SOD1) is one of the main antioxidant enzymes, and seems to play essential roles in corpus luteum (CL) function by regulating the production of reactive oxygen species (ROS). To determine the luteolytic mechanisms of prostaglandin F2α (PGF) in bovine CL, we examined the effects of PGF on SOD1 expression and total SOD activity during PGF-induced luteolysis in vivo and in cultured luteal cells in vitro. Bovine CL tissues were collected at different stages of the estrous cycle and at 0, 0.5, 2, 12 and 24 h after PGF administration (0 h) on Day 10 post-ovulation (n=5 CL). Mid-luteal cells were exposed to PGF (0.1-10 µM) and H2O2 (1-100 µM) for 2 h and 24 h. SOD1 mRNA and SOD activity increased from the early to late luteal stage, then decreased (P<0.05) at regressed luteal stage. Interestingly, PGF and H2O2 increased SOD1 mRNA, protein and SOD activity at 2 h but suppressed at 24 h in cultured luteal cells. In the CL collected from conscious cattle, SOD1 protein and SOD activity increased between 0.5 and 2 h and decreased to the lowest level at 24 h after PGF treatment. Furthermore, H2O2 increased PGF production by luteal cells in a dose and time dependent–manner. In summary, PGF induced a biphasic regulation of SOD in bovine CL as well as cultured luteal cells according to the time of exposure. The overall findings suggest that the decrease in luteal SOD is important to enhance ROS production and to ensure the regression of bovine corpus luteum.
