Human Prolactin

Prolactin is a secreted neuroendocrine pituitary hormone acting primarily on the mammary gland to promote lactation, and it is synthesized mainly by the anterior pituitary in all mammals, where secretion is under tonic inhibition by hypothalamic dopamine. Prolactin expression is low during early human pregnancy, but increases in late pregnancy. The prolactin receptor is a transmembrane type I glycoprotein whose expression is widespread. Each prolactin molecule is thought to bind two receptor molecules. Prolactin may play roles in breast and prostate cancer development, regulation of reproductive function, and immunoregulation (1-5).