In situ detection of prolactin receptor mRNA and apoptotic cell death in mouse uterine tissues with adenomyosis.

Prolactin receptor (PRLR) mRNA was visualized by in situ hybridization in adenomyotic uteri of mice with ectopic pituitary grafting. The signals of PRLR mRNA were mainly detected in the smooth muscle cells of myometrium and the epithelial cells of uterine glands and lumen. In the uteri with adenomyosis, the expression intensity was stronger than that in the normal uteri of control mice. This might reflect the higher serum prolactin (PRL) levels in the mouse with pituitary graft, as reported previously. Electron microscopic observation showed that apoptotic cell death occurred in certain cells in the myometrium bearing adenomyotic changes. Such changes were rarely observed in the normal uteri. The relevance of these findings to the development of adenomyosis was examined.