Distribution of progesterone receptor in female mouse tissues

Two novel antibodies against the mammalian progesterone receptor (PR) were raised and characterized to study the distribution of PR and the effect of estrogen on PR expression in various female murine tissues by immunohistoch emistry. There were estrogen-independent constitutive PR expressions in the smooth muscle cells of uterus, uterine blood vessels, urinary bladder, duo denum, and jejunum of ovariectomized mice. Uterine stromal cells, capsular cells of kidney and adrenal gland, and the epithelial cells of submandibula r gland expressed PR constitutively. PR expression was detected in some thy mic cells and the number of PR-positive thymic cells increased markedly aft er estrogen treatment. Estrogen induced PR expression in the epithelial cel ls of uterus, vagina, urethra, and skin and the stromal cells of vagina, ur ethra, and pancreatic ducts, as well as the smooth muscle cells of some blo od vessels. These results suggest cell-specific progesterone actions in the urinary tract, skin, and gastrointestinal organs, on the immune functions, and on the regulation of local blood flow. (C) 1999 Academic Press.