Abstract
Ovulation inducing activity of unfractionated sheep pituitary gonadotrophin (Vetrophin) was compared with that of HCG.
One rat ovulating unit3) of Vetrophin was 1/26.7 R. U. by subcutaneous administration and 1/256 R. U. by intravenous injection. The ovulation inducing potency of intravenous injection was about 9.5 times active than that of subcutaneous injection. The ratio of effectiveness of subcutaneous and intravenous injection is almost the same as the results obtained by HCG6).
The potency of Vetrophin is shown by Rat Unit which is determined by the ovarian weight stimulating effects. However, based on the rat ovulating unit, 1 R. U. of Vetrophin coresponds to about 180 to 280 I. U. or 60 to 70 M. U. of HCG by subcutaneous injection and to about 370 I. U. of a preparation of HCG by intravenous injection.
It is said that in terms of HCG tested on the increment of ovarian weight in immature rats, Vetrophin provides the equivalent of 2, 000 I. U. in the 1 R. U. dose8, 11). However, compared by the ovulation inducing activity, 1 R. U. of Vetrophin was equivalent to only about 200 or 400 I. U. of HCG by subcu-taneous or intravenous administration respectively. Vetrophin is used mainly by the intravenous injection for the treatment of the reproductive disorders of domestic animals. On the contrary, HCG is usually not administered intravenously. Considering our results, it should be said that the effect of 1 R. U. of Vetrophin (intravenous injection) to treat the cystic ovaries may be as same as the effect of about 2, 000 I. U. or about 1, 000 M. U. of HCG (subcutaneous injection). The results presented here will furnish some information to clinical use of Vetrophin. Finally, we suggest that in the treatment of cystic ovaries, Vetrophin may be used effectively to treat the cases that antihormone against HCG is produced by previous injections of HCG.
