Normalization of glucose entry under the high glucose condition by phlorizin attenuates the high glucose-induced morphological and functional changesof cultured bovine retinal pericytes

We previously reported that sodium-dependent glucose uptake is present in b ovine retinal pericytes and that phlorizin normalizes its glucose consumpti on under high glucose conditions. To clarify the effect of phlorizin on mor phological and functional change of retinal pericytes under high glucose co nditions, retinal pericytes were incubated in media with 5 mM glucose, 30 m M glucose, and 30 mM glucose plus 0.2 mM phlorizin for 7 days. The diameter of cells in the concentrations of glucose more than 10 mM were significant ly larger than those in 5 mM glucose and 30 mM glucose plus phlorizin. Gluc ose, sorbitol and fructose contents of the cells in 30 mM glucose were sign ificantly increased compared with those in 5 mM glucose, and were normalize d by phlorizin. Thymidine uptake in the concentrations of glucose more than 20 mM was significantly decreased compared with that in 5 mM glucose. Myoi nositol uptake, and DNA in 30 mM glucose were significantly reduced, and we re normalized with phlorizin. Myoinositol content in 30 mM glucose was the same as that in 5 mM glucose, but was significantly decreased by phlorizin. The ratios of glucose to sorbitol or fructose in 30 mM glucose were signif icantly decreased, compared with those in 5 mM glucose and 30 mM glucose pl us phlorizin. Therefore, the cellular enlargement and decreased DNA synthes is in cultured bovine retinal pericytes with abnormal glucose metabolism un der high glucose conditions are attenuated by phlorizin, independent of the cellular myoinositol content. (C) 1999 Elsevier Science B.V. All rights re served.