Abstract
In both rats and primates, including humans, serum levels of insulin-like growth factor I (IGF-I) increase during the onset of puberty, suggesting a role for IGF-I in this process. We examined the ability of IGF-I to affect the release of hypothalamic luteinizing hormone releasing hormone (LHRH) in prepubertal female rats. Our results indicate that IGF-I acts on the median eminence, which contains the highest density of type 1 IGF receptors in the brain, to elicit a dose-related increase in LHRH release. In this regard, a minimal effective dose of 10 ng/ml (p<0.05) and a maximal effective dose of 100 ng/ml (p <0.01) was observed. IGF-II and insulin were one order of magnitude less effective. The results demonstrate that IGF-I has the capability to act directly upon the median eminence to effect release of LHRH, thereby suggesting a role for IGF-I in facilitating peripubertal changes in LHRH release. Thus, IGF-I may represent one of the "metabolic signals' thought to be involved in the initiation of puberty.
Original language | English (US) |
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Pages (from-to) | 420-423 |
Number of pages | 4 |
Journal | Neuroendocrinology |
Volume | 54 |
Issue number | 4 |
DOIs | |
State | Published - 1991 |
Externally published | Yes |
Keywords
- Female puberty
- Insulin-like growth factor I
- Luteinizing hormone releasing hormone
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrinology
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience