QUANTITATIVE STUDIES OF THE OPENING OF THE VAGINA OF IMMATURE RATS FOLLOWING INJECTION OF FEMALE BLOOD AND URINE

Abstract

RECENTLY Hartman and Littrell (1945) reported a new test for estrogens in minute amounts of blood. This test was based on the ability of estrogens to open the vagina of 16 to 21 day old rats. Their method was said to be sufficiently sensitive to detect the amount of estrogen in 0.02 cc. of blood from the finger of normally menstruating women. The reported simplicity and sensitivity of this test made it seem advisable to standardize it for use in estrogen assays. However, when studies similar to those of Hartman and Littrell (1945) were conducted in this laboratory, it became evident that the estrogen content of blood and urine was insufficient to be detected by this method. Therefore, an attempt was made to enhance its sensitivity by priming the animal with small doses of estrogens injected subcutaneously.