[Biochemical mechanisms in the pathogeny of diabetic retinopathy].

Hyperglycemia becomes pathogenic for specific cells through multiple biochemical mechanisms. First, we describe the activation of polyol pathway. Then, we discuss the intracellular production of advanced glycation end product precursors and the activation of protein kinase C system. Also, we talk about the increased hexosamine pathway activity. All of these mechanisms are initiated by the same phenomena, the hyperglycemia-induced mitochondrial production of superoxid which is equal with increased intracellular oxidative stress.