Sorbitol pathway in the ciliary body in relation to accumulation of amino acids in the aqueous humor of alloxan-diabetic rabbits.

The activity of the enzymes, aldose reductase and polyol dehydrogenase, associated with sorbitol pathway were determined in the rabbit ciliary body and compared with the activity of these enzymes in the lens and the retina, a tissue which has the same embryologic origin as the ciliary body. Despite the presence of the two enzymes, no sorbitol could be detected in the ciliary body of diabetic rabbits. These results suggest that the accumulation of sorbitol in the ciliary body and presumably in the ciliary epithelial cells, which are responsible for transport, is not a contributory factor in the reduction of amino acid levels observed previously in the aqueous humor of these animals. The reasons why sorbitol does not accumulate in the ciliary body of diabetic rabbits despite the presence of the necessary enzyme systems are discussed.