Coenzyme dependency of alcohol dehydrogenase in the retina of the rat: IV. Retinol dehydrogenase (RDH) activity in the developing normal and retinitis rat retina, and the effect on enzyme activity of increasing concentrations of NAD or NADP

Retinol dehydrogenase activity has been determined in the developing normal, and retinitis, rat retina, using NAD and NADP as the coenzymes. Under the experimental conditions employed NADP increases RDH activity almost three-fold compared to NAD. Both types of retina reach peak activity around 3 weeks after birth. Thereafter enzyme activity falls off, particularly in the retinitis retina, the decrease being more marked when NADP is the enzyme. More importantly it has been shown that a quadrupling of NAD in the assay system increases RDH activity to NADP levels. The implications of these findings and their possible roles in vision are discussed.