Polyols Accumulation and Effect of Aldose Reductase Inhibitor in STZ-Diabetic Rats

The pathogenesis of diabetic neuropathy is incompletely understood. The accumulation of sorbitol has been postulated to be an important cause of the neuropthy. However, deficiency of myoinositol in diabetic peripheral nerves has also been documented and suggested as a cause of the neuropathy. The relative importance of sorbitol accumulation and myoinositol deficiency is not known and these two processes have usually been regarded as independent phenomena. In Streptozotocin diabetic rats, the centrations con of these two metabolites can be normalized by treatment with Sorbinil (5mg/kg body weight). These results suggest that the two processes are inter-related. The deficiency of nerve myoinositol can also be demonstrated in galactosaemic rats and again this can be normalized by aldose reductase inhibition. These results suggest that sorbitol or galactitol accumulations are primary events which lead to myoinositol deficiency. The finding of a relationship between sorbitol and myoinositol metabolism provide a unified concept relating the two abnormalities of diabetic nerve in the pathogenesis of diabetic neuropathy.