The presence of luteinizing hormone/human chorionic gonadotropin receptors in lactating rat mammary glands.

Previous studies have implied that mammary glands might contain luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptors. But no one ever previously investigated them. We now demonstrate, by using several techniques, that lactating rat mammary glands contain LH/hCG receptor mRNA transcripts and receptor protein which can bind 125I-hCG. Primarily mammary epithelial cells, and to a lesser extent the interductal stromal cells, contain the receptor transcripts and the receptor protein. These findings support the concept that mammary glands are also the targets of direct regulation by LH/hCG.