Abstract: Progesterone receptors in reproductive system (including ovary,fallopian tube,uterus and vagina),pituitary gland and cerebrum of female mice were studied by immunocytochemical LSABmethod in order to show the distribution of receptors and the relationship between the receptors and blastula implantation.Progesterone receptors distributed mainly in uterus and vagina,and only a few in fallopian tube.The receptors were located in nuclei, but not in cytoplasm.No positive reaction could be detected in ovary, pituitary gland and cerebrum.The amount changes of the receptors in the endometrial epithelium and the uterine stroma were consistent with the development of blastula implantation.These data suggest that the progesterone receptors are closely related with the endometrial preparation for blastula implantation.

Key words: progesterone receptor, mouse, reproductive system, pituitary gland, cerebrum, immunocytochemistry