Concepedia

Abstract

IN SOME OF THE EARLIEST STUDIES on ovarian hormones the assay methods were based on the growth of the uteri in normal or castrated immature rabbits, rats, or mice (i, 2). No detailed study of this reaction in normal immature rats was made until Astwood and others (3, 4) determined the most favorable experimental conditions for a sensitive estrogen test based on an increase in uterine weight. They showed that this method is much more sensitive than the spayed rat vaginal smear method. However, the uterine weight response in the immature albino mouse to gonadotropins is much more uniform and more sensitive than in the rat (5–9). These favorable reactions led us to investigate the mouse uterine weight response to pure estrogens, androgens, progesterone, and urine and blood extracts. Von Haam (9) used the mouse uterine response for estrogens in urine extracts, but his results cannot be compared with ours because he does not give his methods and results in sufficient detail.