myo-Inositol and sorbitol in erythrocytes from diabetic patients before and after sorbinil treatment.

Erythrocytes from diabetic patients before and after treatment with the aldose reductase inhibitor, sorbinil, were analyzed by a capillary gas chromatographic method for sorbitol and myo-inositol. The mean erythrocyte sorbitol level in the diabetic patients was significantly higher than in the control subjects (13.1 +/- 0.9 and 5.2 +/- 0.3 nmol/ml erythrocytes, respectively, mean +/- SEM, p less than 0.001). The mean erythrocyte myo-inositol level in diabetic patients was not different from that in control subjects (43.2 +/- 2.9 and 40.5 +/- 1.9 nmol/ml erythrocytes, respectively). Sorbinil treatment reduced the elevated sorbitol levels in the diabetic patients to normal or slightly below normal, but did not affect the erythrocyte myo-inositol concentration. It is concluded that the erythrocyte is not a suitable model to monitor a possible effect of sorbinil on myo-inositol concentration in less accessible tissues.