The sorbitol pathway: effect of streptozotocin induced diabetes and the feeding of a sucrose-rich diet on glucose, sorbitol and fructose in the retina, blood and liver of rats.

The sorbitol, fructose and glucose content of the retina, blood and liver from normal and streptozotocin diabetic rats fed either a starch- or sucrose-rich diet for 15 days has been determined. The sorbitol and fructose level in the retina was much higher than that in either the liver or blood and was significantly increased in diabetes on either diet. Such increases in the sorbitol concentration did not occur in either the liver or the blood during diabetes, and the possibility that the sorbitol pathway can play an important metabolic role in the diabetic retina has been discussed. The feeding of a sucrose- as opposed to a starch-rich diet did not significantly alter the concentrations of glucose, sorbitol or fructose in the normal rat retina but caused a marked elevation in the diabetic state.