The insulin-like growth factors I and II stimulate proliferation of different types of Schwann cells.
A combination of immunocytochemistry for glial specific antigens and bromodeoxyuridine (BrdU) and teasing was used to identify proliferating cells in cultured rat sciatic nerve segments. The nerve segments were exposed to insulin, or the insulin-like growth factors IGF-I and IGF-II. Teasing in combination with BrdU immunocytochemistry showed that around 93% of the proliferating cells in the nerve segments were Schwann cells. Immunostaining for BrdU and GFAP (glial fibrillary acid protein) showed that IGF-II enhanced proliferation of Schwann cells surrounding unmyelinated nerve fibres. In contrast, truncated IGF-I promoted proliferation of Schwann cells of myelinated nerve fibres while insulin increased proliferation of both cell types.
Sondell
M
M
Department of Animal Physiology, Lund University, Sweden.
Fex-Svenningsen
A
A
Kanje
M
M
D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D046508:Culture Techniques; D005260:Female; D007150:Immunohistochemistry; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology*; D009186:Myelin Sheath / Q000187:drug effects; D009419:Nerve Tissue Proteins / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D012583:Schwann Cells / Q000145:classification / Q000166:cytology / Q000187:drug effects*; D013268:Stimulation, Chemical; D013936:Thymidine / Q000378:metabolism
D007328:Insulin; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D001973:Bromodeoxyuridine; D013936:Thymidine