... consistent with the ADH4 activity previously found in this epithelium [25]. Thus, the presence in the RPE, the high activity with 11-cis-retinol, and the specificity for the oxidation direction of the ... ADH4 is detected in the retinal pigment epithelium (RPE) and itis extensively distributed in the retina. ADH4is found in the outer (ONL) and the inner(INL) nuclear layers, in the inner plexiformlayer ... the neural retina, together with the presence of receptors and otherproteins related to retinoic acid [21,60,61], indicate acomplex retinoid metabolism and signaling in retina, with the probable...