The regeneration of visual purple: its relation to dark adaptation and night blindness

Bleaching experiments on eyes of living guinea‐pigs

“…Representative samples of standard errors are indicated in a few instances. Tansley (1931) found that the rate of regeneration of visual purple in the rat showed a seasonal variation, and some seasonal effect might have been expected in the present measurements. The rate of regeneration, however, is not necessarily related to the total available amount of visual purple, which may explain why no measurable seasonal variation in the amounts of pigments bleached could be detected here.…”

Cytochemical demonstration of guanylate cyclase activity in retinal photoreceptors with special reference to changes under light and dark adaptation.

“…A longer time was required if the rat was in very bright light prior to being dark adapted. Rhodopsin regeneration in the rat is quite slow and 3-4 hr are needed for complete recovery after a full bleach (32,40,45) . Dowling (14) reported that dark adaptation in the rat is rapid until the eye is adapted to light strong enough to bleach a measurable fraction of rhodopsin, and after brighter light adaptation, dark adaptation consists of two parts : an initial rapid phase followed by a slow component, and it takes 2-3 hr to complete after a full bleach of rhodopsin.…”

On Rhodopsin in Solution

“…Rhodopsin solutions were prepared by leeching retinas of dark adapted animals for various periods at room temperatures with a 2 per cent aqueous solution of crystalline digitonin (Tansley, 1931). Special care was taken during the dissection of the tissues to remove all apparent traces of choroid and pigment epithelium.…”