Pre- and post-ovulatory changes in carbonyl reductase in ovarian follicles and corpora lutea in rats
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Abstract:
We investigated the relationship between the carbonyl reductase (CR) and the ovarian function in normal cycling and gonadotropin treated rats. The preovulatory mature large follicles, the neo corpora lutea (CL) after ovulation, and the old CL were isolated from the other ovarian component. The CR activity (4-benzoylpyridine reducing activity) in the preovulatory mature large follicles did not change between 1500 h and 1900 h on the day of proestrus. In the neo CL after ovulation, the activity and concentration of the enzyme were significantly increased to 2.2 and 1.7 times, respectively, of the levels in the mature large follicles. The enzyme activity and its concentration in the old CL were the lowest. The enzyme activity in the neo CL after human chorionic gonadotropin (hCG) treatment in equine chorionic gonadotropin (eCG)-pretreated rats was also increased to 1.9 times of that in the mature large follicles formed by treatment with eCG alone. Positive immunohistochemical localization of ovarian CR was observed in the neo CL formed on the day of estrus and after hCG treatment. The results suggest that the rat ovarian CR is involved in the formation of neo CL after ovulation rather than the ovulatory process.
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