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Growth promoting effects of IGF‐I on fetal hypothalamic cell lines under serum‐free culture conditions
Author(s) -
TorresAleman Ignacio,
Naftolin Frederick,
Robbins Richard J.
Publication year - 1989
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(89)90069-5
Subject(s) - endocrinology , cell culture , medicine , growth factor , biology , cell growth , receptor , hypothalamus , in vitro , endogeny , insulin , cell , insulin like growth factor , thymidine , somatomedin , fetus , fetal bovine serum , cell division , biochemistry , genetics , pregnancy
Recent evidence indicates that the insulin‐like family of peptides may act as endogenous trophic factors in the central nervous system. To further examine this possibility we have investigated the effects of three insulin‐like peptides on the in vitro growth of fetal hypothalamic cell lines. Two virally transformed rat hypothalamic cell lines which have been developed in our laboratory (A‐6 and F‐12) were used. Cells were plated at varying densities and cultured in the presence or absence of either insulin‐like growth factor I (IGF‐I), insulin, or multiplication stimulating activity (MSA or IGF‐II), in serum‐free medium for 1 wk. Cell growth was assessed by counting or by measuring cellular incorporation of 3 H‐thymidine. Of the three peptides tested IGF‐I was the most potent in eliciting cell growth. Insulin also stimulated growth of both cell lines, but was 100 times less potent for A‐6 cells while it was equipotent with IGF‐I in F‐12 cells. MSA had no effect on either cell line. Both IGF‐I and insulin showed dose‐response effects in increasing cell growth. We also found that the two cell lines had the greatest response to IGF‐I at low cell densities. Finally, time‐course experiments suggested that a continued presence of the peptide is essential for the growth‐promoting effects. We conclude that IGF‐I is a potent growth factor for virally transformed cell lines derived from the rat fetal hypothalamus. Since both IGF‐I immunoreactivity and IGF‐I receptors have been located in this diencephalic area these results suggest that IGF‐I may constitute a mitogenic signal for hypothalamic cells during neurogenesis.