Insulin-like growth factor I as an intraovarian regulator: basic and clinical implications.

Abstract

Although much remains to be learned with respect to the possible relevance of IGF-I to ovarian physiology, it may be possible at this time to tentatively formulate possible functions of IGF-I in this connection: 1. Amplification of gonadotropin hormonal action--a key requirement given the exponential nature of follicular development. 2. Integration of follicular development--an essential facet concerned with the coordination of granulosa-theca cooperation. 3. Selection of dominant follicle(s)--a speculative proposition assuming timely and selective activation of the IGF-I system in "chosen" follicles. Aside from its possible role(s) in the course of established follicular cycles, IGF-I (and/or IGF-II) may also participate in the very formation of the follicular apparatus during the late fetal/early neonatal period. Although the ovary is gonadotropin-independent at that time, we previously showed that IGF-I may well interact with VIPergic input now implicated in the morphodifferentiation of the follicular apparatus. Similarly, IGF-I may be concerned with the promotion of juvenile and early pubertal follicular gonadotropin (FSH) levels; ovarian IGF-I may have a bearing on the puberty-promoting effect of growth hormone. Indeed, an association appears to exist between isolated growth hormone deficiency and delayed puberty in both rodents and human subjects, a process reversed by systemic growth hormone replacement therapy. Given that ovarian IGF-I and its receptor may be growth hormone-dependent, it is tempting to speculate that the ability of growth hormone to accelerate pubertal maturation may be due, at least in part, to the promotion of ovarian IGF-I production and reception with the consequent local potentiation of gonadotropin action.

• Authors: E Y Adashi, C E Resnick, E R Hernandez, A Hurwitz, C T Roberts, D Leroith, R Rosenfeld
• Journal: Annals of the New York Academy of Sciences (Ann N Y Acad Sci) Vol. 626 Pg. 161-8 ( 1991) ISSN: 0077-8923 [Print] United States
• PMID: 1711822 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S., Review)

Chemical References

• Carrier Proteins
• Insulin-Like Growth Factor Binding Proteins
• Receptors, Cell Surface
• Receptors, Somatomedin
• Insulin-Like Growth Factor I

Topics

• Animals
• Carrier Proteins (biosynthesis)
• Female
• Granulosa Cells (physiology)
• Insulin-Like Growth Factor Binding Proteins
• Insulin-Like Growth Factor I (metabolism, physiology)
• Ovary (metabolism, physiology)
• Receptors, Cell Surface (physiology)
• Receptors, Somatomedin