Testosterone Concentrations in the Peripheral Plasma of Androgenized Female Rats and in the Estrous Cycle of Normal Female Rats

Abstract

Previous in vitro data have suggested that the ovaries of androgen sterilized female rats (ASFR) have the capacity to incorporate more labeled precursors into androgens than ovaries from normal rats. In order to test the biosynthetic capacity of the ASFR ovary in vivo, the following experiments were carried out. Blood was collected from 120-day-old intact, castrated or adrenalectomized ASFR. In addition, blood was collected from diestrous, estrous, proestrous, adrenalectomized proestrous and castrated female rats. The plasma was assayed for testosterone by a radioimmunologic system which did not require chromatography. The plasma testosterone concentration in ASFR was lower than that found in proestrous and diestrous females, similar to that found in estrous females, and higher than that found in castrated females. The proestrous females had significantly higher peripheral testosterone concentrations than either estrous or diestrous females. Furthermore, the testosterone concentration in the peripheral blood of ASFR was found to be significantly higher than that in castrated and adrenalectomized ASFR and not significantly different from adrenalectomized proestrous females. In the castrated ASFR, peripheral testosterone was higher than in adrenalectomized ASFR and similar to castrated females. (Endocrinology95: 26, 1974)