The human uterus repeatedly exhibits cyclic biochemical and cytological changes during the reproductive period of life. These changes are the result of a well-characterized endocrine network involving the hypothalamus, pituitary, and ovary. The exact nature of the mechanism(s) by which the sex steroids act on the uterus remains to be elucidated. Possible local mediators of hormonal action on the uterus include polypeptide growth factors. Using the method of RNA transfer blot hybridization, we have analyzed tissue samples from the cycling human endometrium and tissue samples of human myometrium and myometrial benign tumor (leiomyoma) for the presence of platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF) RNA. All the uterine tissues examined possessed RNA for PDGF-B chain and IGF-I and -II. Two transcripts were observed for PDGF-B chain, four were observed for IGF-I, and eight were observed for IGF-II. Overall, the relative abundance of PDGF-B chain RNA was consistent in all of the uterine tissues examined. In contrast, IGF RNA relative abundance varied. IGF-I RNA was highest in late proliferative stage endometrium, and IGF-II RNA was highest in early proliferative stage endometrium. Both IGF-I and IGF-II RNAs were greater in amount of leiomyoma than in myometrium. The increased IGF-I RNA in late proliferative-stage human endometrium correlates with the known elevation of estradiol secretion by the ovary and the increased concentration of uterine estradiol receptors during this stage of the menstrual cycle.(ABSTRACT TRUNCATED AT 250 WORDS)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.