PROGESTERONE INDUCED MODULATIONS OF SERUM HORMONAL PROFILES IN ADULT MALE AND FEMALE RATS

Abstract

The impact of progesterone on serum hormonal profiles in the presence and absence of gonads was studied in adult male and female albino rats. Progesterone was administered intramuscularly for 30 days at a dose of 1 mg/100 g body weight/day. Serum testosterone, estradiol and prolactin titres decreased in male and female rats with intact gonads given progesterone. While the levels of both luteinizing hormone (LH) and follicle stimulating hormone (FSH) decreased in male rats with intact gonads, only FSH decreased in female rats. The inhibitory effect of progesterone on serum estradiol, LH, FSH and prolactin persisted even after gonadectomy in male rats. This persistent inhibitory effect of progesterone was also seen on serum testosterone, FSH and prolactin levels of female rats. Ovariectomy modified progesterone action on LH, as is evident from the decreased levels of LH observed only in ovariectomized rats given progesterone. While progesterone had no effect on serum T3 and T4 in male rats, gonadectomy altered the levels of T3 and T4 in male and female rats. Progesterone increased the levels of T3 and decreased the levels of T4 in ovariectomized rats. Growth hormone (GH) and thyroid stimulating hormone (TSH) levels seem to be resistant to changes in progesterone titre, irrespective of the sex and gonadal status. The present data suggest the existence of a sex specific effect of progesterone on gonadotrophins. The data on T3, T4 and TSH reveals that progesterone has no effect on the pituitary thyroid axis in the presence of gonads.