Concentration that causes a 50% inhibition of partially purified calf lens aldose reductase with glyceraldehyde as substrate. Single determination; the reproducibility of the assay did not vary by more than 10%? Oral dose, given tid, that causes a 50% reduction in sorbitol levels of sciatic nerve of streptozotocinized rats. 8 If the> or< sign is used, the percent inhibition found is shown in parentheses; in these cases, the percent inhibition produced ...