Insulin-like growth factor I and II binding in human myometrium and leiomyomas.

Abstract

The purpose of this study is to determine if the human myometrium has receptors for insulin-like growth factors I and II and whether the concentration of these receptors is increased in leiomyomas. Specific binding of iodine 125-labeled insulin-like growth factor I and II was examined in the membrane preparations of myometrium and leiomyomas obtained from 10 women with uterine leiomyomas. Binding studies indicate presence of specific binding sites for both insulin-like growth factors I and II in the myometrium and leiomyoma. The concentration of binding sites for insulin-like growth factor I, but not for insulin-like growth factor II, was significantly (p less than 0.01) higher in leiomyomas than in the myometrium. The dissociation constants for insulin-like growth factors I and II receptors in both myometrium and leiomyoma were similar. insulin-like growth factor I, but not insulin-like growth factor II, receptors are increased in leiomyomas compared with those in myometrium, indicating that insulin-like growth factor I may play a role in the generation and/or growth of this tumor.