COMPARISON OF SENSITIVITIES OF THE IMMATURE AND PREGNANT MOUSE FOR ESTIMATION OF GONADOTROPIN

Abstract

BOTH increase in weight of reproductive organs in the immature mouse and ovulation in the pregnant mouse have been demonstrated as responses to gonadotropins. These responses have been and still are used as tests for potency of gonadotropic substances. As yet, however, the relative sensitivities of assays using the immature and pregnant mouse apparently have not been reported. A comparison of these responses was undertaken therefore, using as a source of gonadotropin the unfractionated, dried pituitary glands collected from mice shortly after parturition. Observations for parturition were made in a manner similar to that used in an earlier study (Runner and Ladman, 1950). A brief account of the data on comparative sensitivities of the 2 assays has been reported previously (Ladman, 1949). The immature female mouse was shown by Aschheim and Zondek (1928) to respond to the gonadotropin in urine of pregnant women.