EDITORIAL Physiological and Pathological Relevance of

he concept that LH and hCG can directly regulate uterine functions by activating their common G-pro-tein coupled receptor in the uterus comes from nu-merous studies published around the world in the last 20 years."12 It has been demonstrated that the uterus of many species contains LH/hCG receptors, and their activation in vitro or in vivo results in numerous changes that contribute to pregnancy initiation and maintenance.1'2 The uterus contains more total receptors than the ovary and receptors have been detected in the endometrium, myometrium, blood vessels, and resident macrophages by multiple techniques."12 Endometrial epithelial cells contain more receptors than other uterine cells, and receptor content increases from the proliferative to the secretory phase and declines to very low levels after menopause."1