ACETYL-L-CARNITINE CORRECTS THE ALTERED PERIPHERAL-NERVE FUNCTION OF EXPERIMENTAL DIABETES

Acetyl-L-carnitine (ALC) has been shown to facilitate the repair of tr ansected sciatic nerves. The effect of ALC (50 mg/kg/d) on the diminis hed nerve conduction velocity (NCV) of rats with streptozotocin (STZ)- induced hyperglycemia of 3 weeks' duration was evaluated. The aldose r eductase inhibitor, sorbinil, which is reported to normalize the impai red NCV associated with experimental diabetes, was used as a positive control. Aldose reductase inhibitors are thought to have an effect by decreasing peripheral nerve sorbitol content and increasing nerve myo- inositol. Treatment of STZ-diabetic rats with either ALC or sorbinil r esulted in normal NCV. Sorbinil treatment was associated with normaliz ed sciatic nerve sorbitol and myo-inositol; ALC treatment did not redu ce the elevated sorbitol levels, but sciatic nerve myo-inositol conten t was no different from nondiabetic levels. Both ALC and sorbinil trea tment of STZ-diabetic rats were associated with a reduction in the ele vated malondialdehyde (MDA) content of diabetic sciatic nerve, indicat ing reduced lipid peroxidation. The beneficial effects of sorbinil and ALC on the altered peripheral nerve function associated with diabetes were similar, but their effects on the polyol pathway (frequently imp licated in the pathogenesis of peripheral neuropathy) were different. Copyright (C) 1995 by W.B. Saunders Company