PROLACTIN BINDING-SITES IN NORMAL UTERUS AND THE UTERUS WITH ADENOMYOSIS IN MICE

Radioreceptor assay for mouse prolactin (mPRL) was developed in the mo use uterus. The specific binding of [I-125]-mPRL to the uterine prepar ations was demonstrated and the binding was found to have a similar af finity to that in the liver preparations. The specific PRL-binding to the uterine preparations tended to increase after estrogen treatment, while the differences among the three groups, diestrous intact, ovarie ctomized, and ovariectomized and estrogen-treated mice, were statistic ally not significant. Immunohistochemical staining of PRL revealed tha t PRL immunoreactivity was preferentially localized in the myometrial cells. Pituitary grafting into the uterus induced a high incidence of adenomyosis associated with the increase in plasma PRL levels. Further more, the PRL-binding activity in the uterus with adenomyosis was sign ificantly higher than that in normal uterus. These results indicate th at the elevation of PRL binding in the uterus, hyperprolactinemia, and the development of adenomyosis are interrelated.