Nuclear uptake of radioactivity by cells of pituitary, brain, uterus, and vagina of the asian musk shrew ( Suncus murinus) following [ 3H]estradiol administration

Abstract

Many reproductive traits of the Asian musk shrew ( Suncus murinus) appear to be independent of ovarian influence, even though [ 3H]estradiol is taken up by uterus and vagina in vitro. This study seeks to examine in situ nuclear uptake of radioactivity by brain, pituitary, uterus, and vagina following [ 3H]estradiol administration. Ninety minutes after injection of [ 3H]estradiol, tissues were processed for either dry autoradiography or thaw-mount autoradiography. In the brain major accumulations of labeled neurons occurred in the medial preoptic nucleus, medial amygdaloid nucleus, lateral septal nucleus, arcuate nucleus, and ventrolateral part of the ventromedial nucleus. The anterior lobe of pituitary contained more than 70% labeled cells, with immunocytochemically stained gonadotropes among the most heavily labeled. The posterior lobe contained scattered labeled cells. In the uterus and vagina stromal and myometrial cells were heavily labeled while epithelial cells were moderately to lightly labeled. The data are discussed in relation to other eutherian species and with respect to current physiological data on the musk shrew.