Effect of clomid, sexovid and prostaglandins on induction of ovulation and gonadotropin secretion in a freshwater catfish, Heteropneustes fossilis (Bloch).

The effect of clomid, sexovid and some prostaglandins (PGE1 and PGF2alpha) on the induction of ovulation, ovarian activity and gonadotropin concentration in the pituitary and blood serum was studied in H. fossilis. Sham-hypophysectomized individuals recorded a very high percentage (90--100%) of ovulation on the 6th day of clomid (150 mug), sexovid (150 mug), PGE1 (100 mug) and PGF2alpha (100 mug) administration. Amongst hypophysectomized recipients only sexovid treated ones ovulated (78%). These drugs were very effective in promoting the ovarian activity in intact specimens but, except sexovid, failed to stimulate any response in hypophysectomized subjects. The gonadotropin concentration in the pituitary gland and blood serum was also elevated after the treatment with the above compounds. It is quite evident from the data that clomid, PGE1, and PGF2alpha, probably acting via hypothalamus, accelerate the synthesis and release of gonadotropin which in turn induces hightened ovarian activity resulting in ovulation. Sexovid seems to have twofold action-- the one indirect through hypothalamus leads to hypophysis leads to ovary like clomid and prostaglandins, and the other directly upon the ovary, possibly by increasing its response to the available gonadotropin, or by behaving like LH.