title: Human retinal pigment epithelium in vitro: influence of low oxygen tension, glucose and insulin.
abstract: Retinal pigment epithelium (RPE) cells migrating through the damaged retina into the vitreous body seem to play an important role for the pathogenesis of proliferative vitreoretinopathy (PVR) and other proliferative retina diseases. It is so far not known how the RPE cells are able to survive in the vitreous body without contact to the blood vessels of the choroid supplying them with oxygen and nutritive substances. To answer this question, we studied growth characteristics and sensitivity to glucose and insulin of human RPE cells, incubated with reduced oxygen partial pressure. In the first study, RPE cultures of 58 postmortem human eyes were grown with 5% O2/5% CO2 and with standard conditions (20% O2/5% CO2). The growth was assessed in five graded stages. Our data show that human RPE grows better under 5% oxygen than under 20% O2 (p < 0.0001). In consideration of this effect, we cultivated, in a further study, pigment epithelium of 49 postmortem human eyes with 5% oxygen and with 4 different glucose concentrations with and without addition of insulin. We found that glucose in higher concentrations was a potent stimulator of growth, whereas insulin was a modest stimulator when used alone. The combination of glucose and insulin was significantly more effective (p = 0.01) in the period of the first 7 days. These results suggest that proliferation of human RPE cells can be increased by oxygen reduction, glucose and insulin. These interactions may help in understanding the pathophysiology of retina damage and proliferative retina diseases like PVR.
authors.affiliation: Department of Ophthalmology, University of Erlangen-Nürnberg, FRG.
authors.forename: H L
authors.initials: HL
authors.lastname: Knorr
authors.forename: M
authors.initials: M
authors.lastname: Linde-Behringer
authors.forename: B
authors.initials: B
authors.lastname: Gossler
authors.forename: U M
authors.initials: UM
authors.lastname: Mayer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002455:Cell Division; D002478:Cells, Cultured; D002648:Child; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D050356:Lipid Metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D010100:Oxygen / Q000494:pharmacology*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000378:metabolism*
chemical_list: D007328:Insulin; D005947:Glucose; D010100:Oxygen