Interrelations of Visual Pigments and “Vitamins A” in Fish and Amphibia

摘要: In frogs and fish, although perhaps not in mammals (1, 2), the pigment epithelium plays a decisive role visual regeneration (see Baumann, 3, for review). This is illustrated Fig. 1 Rana clamitans, frog where retina may be separated easily cleanly from rest of pigmented layers eye. As figure shows, isolated at 20° regenerates only about 11% bleached (98%) by ½ hr. exposure to yellow light λ >460 nm (cf. Wald Hubbard, 4; Ewald Kuhne, 5). On other hand, after similar bleach opened eye cup 76–95% (compare ref. 6), while stripped away its then replaced as much 55– 88% 7). The amount regenerated appears somewhat lower when separated, replaced, but it still considerably more than retina.