A STUDY OF THE PITUITARY FACTOR INCREASING THE OVARIAN WEIGHTS OF IMMATURE RATS WHEN INJECTED IN COMBINATION WITH PREGNANCY URINE

Abstract

Littermate immature [female] rats were treated with pregnancy urine extract, growth-free gonadotropic hypophyseal extract and a combination of both. The increase in weight of the ovaries of the rats produced by the combination of these extracts was greater than the sum of the increases produced by each substance alone. This synergistic action named "augmentation" was also secured by combining alkaline extracts of sheep, beef, pig and human hypophyses with pregnancy urine, though results obtained with human pituitaries were not outstanding. Urinary follicle stimulating extracts and pregnancy urine give similar results in normal and hypophysectomized immature rats. It is suggested that augmentation is dependent on a differential action of 2 gonadotropic hormones which together produce greatly enlarged ovaries.