ACETYL-L-CARNITINE CORRECTS ELECTRORETINOGRAPHIC DEFICITS IN EXPERIMENTAL DIABETES

Acetyl-L-carnitine reduces the latencies of electroretinogram oscillat ory potentials in healthy humans. The effect of acetyl-L-carnitine (50 mg . kg-1 . day-1) on the increased electroretinogram latencies found in rats with STZ-induced hyperglycemia of 3-wk duration was evaluated . The aldose reductase inhibitor sorbinil, which has been shown to nor malize abnormal electroretinogram tracings associated with STZ-induced diabetes, was used as a positive control. Aldose reductase inhibitors are thought to lower tissue sorbitol while increasing myo-inositol. T he electroretinograms of the STZ-induced diabetic rats in this study w ere abnormal; treatment with acetyl-L-carnitine as well as sorbinil si gnificantly improved electroretinogram b-wave amplitude and decreased the latencies of oscillatory potentials 2 and 3. Acetyl-L-carnitine tr eatment of STZ-induced diabetic rats did not affect hyperglycemia or e rythrocyte polyol pathway activity as reflected by erythrocyte sorbito l levels. In contrast, sorbinil did reduce elevated erythrocyte sorbit ol levels. This suggests that the impaired electroretinograms associat ed with STZ-induced diabetes may not be caused solely by increased pol yol pathway activity.