ABSTRACT
Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) share a common receptor
in gonadal cells; however, the presence of these receptors has also been detected
in several nongonadal but reproduction-associated tissues of pig, human, and other
species. There are no data about the ontogeny of the human LH/hCG receptor. The expression
of the porcine LH receptor gene in the uterus starts about 10 days after the appearance
of this gene in gonads. LH/hCG receptors were found in uterus (myometrium, endometrium),
oviduct, cervix, fetal membranes, and umbilical cord in humans and pigs. The main
role of LH/hCG receptors in myometrium is stimulation of growth and hyperplasia and
relaxation of uterine motility. hCG also increases blood flow in the uterine artery.
LH and hCG can increase production of prostaglandins in endometrium, oviduct, and
blood vessels. It is suggested that the preovulatory surge of LH plays an important
role in controlling oviductal contractions. Human and pig mammary glands also possess
LH/hCG receptors through which gonadotropins can affect the metabolism of steroid
hormones in this tissue and may play an inhibitory role in mammary carcinogenesis
and in the growth of breast tumors.
KEYWORD
LH/hCG receptor - reproduction - human - pig