Enhancement and inhibition of mitogenic action of insulin-like growth factor I by high glucose in cultured bovine retinal pericytes.
To explore the possible relationship between insulin-like growth factor I(IGF-I) and diabetic retinopathy, we examined the effects of glucose on IGF-I stimulated thymidine incorporation into DNA and IGF-I binding in cultured bovine retinal pericytes. IGF-I significantly increased thymidine incorporation, and its effect was completely inhibited by IGF-I receptor antibody. The exposure to high glucose for 8 h significantly enhanced the IGF-I induced increase in thymidine incorporation as compared with those to normal glucose and to high osmolarity. In contrast, the incubation with high glucose for 24 h decreased thymidine incorporation in response to IGF-I. Specific binding of IGF-I to pericytes was increased by the incubation with high glucose for both 8 and 24 h. These results suggest that glucose may play an important role in the regulation of mitogenic action of IGF-I in retinal pericytes.
Third Department of Internal Medicine, Nagoya University School of Medicine, Japan.
K
K
Naruse
F
F
Sakakibara
J
J
Nakamura
N
N
Koh
N
N
Hotta
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001667:Binding, Competitive; D002196:Capillaries / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D017526:Receptor, IGF Type 1 / Q000276:immunology / Q000378:metabolism; D012171:Retinal Vessels / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D007334:Insulin-Like Growth Factor I; D004247:DNA; D017526:Receptor, IGF Type 1; D005947:Glucose; D013936:Thymidine