Requirement of insulin or IGF-1 for the maintenance of retinyl ester synthetase activity by cultured retinal pigment epithelial cells.
Previous work from these laboratories showed that the retention of retinyl ester synthetase activity by cultured human retinal pigment epithelium is up to tenfold greater with PM medium (Medium 199 plus insulin, other added defined components, 1% serum and 1% retina extract) than with conventional culture media. The present work shows that insulin is the component of PM medium required for maintenance of ester synthetase activity and that insulin-like growth factor type 1 (IGF-1) also is effective at maintaining ester synthesis. In addition, insulin can maintain ester synthetase activity in cultured rat RPE. Preliminary dose-response measurements provide additional support for these findings and strongly suggest that both insulin and IGF-1 are maximally effective at physiological concentrations (1-10 ng ml-1).
Edwards
R B
RB
Boston University School of Medicine, Department of Ophthalmology, MA 02118.
Adler
A J
AJ
Claycomb
R C
RC
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D009994:Osmolar Concentration; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000201:enzymology*; D051381:Rats; D051142:Retinol O-Fatty-Acyltransferase
D003470:Culture Media; D007328:Insulin; D007334:Insulin-Like Growth Factor I; D000217:Acyltransferases; D051142:Retinol O-Fatty-Acyltransferase