Immunohistochemical evidence for the presence of progesterone receptor in rat submandibular glands.

Immunohistochemical analysis of progesterone receptor was carried out in rat submandibular glands. Immunoreactivity to progesterone receptors was found in cell nuclei of the intralobular duct system within male and female rat submandibular glands. The female glands contained more immunoreactive cells than the male glands. In ovariectomized rats progesterone receptor-containing cells decreased in number while testectomized glands revealed an increase. When estradiol was administered to gonadectomized rats of both sexes, the immunoreactivity in cells of the intralobular duct system markedly increased. These results suggest the possibility that progesterone may modulate various metabolic functions in the rat submandibular glands.