[Changes in the electroretinogram and concentration or rhodopsin in the Hunter strain of rats during development of hereditary retinal degeneration].

Electroretinographic changes as well as rhodopsin content in the isolated retina and the eye cup in Hunter rats were studied during inherited retinal degeneration. The concentration of rhodopsin in the eye cup increases for the first 45 days after birth and then decreases slowly; the visual pigment concentration in the retina reaches its maximum by the 25th day and drops abruptly after the 35th day. The amplitude of the electroretinographic b-wave evoked by near-threshold and saturating stimuli decreases evenly till 35th day. After this day the threshold drastically increases and a-wave disappears. Thus, the 35th day is crucial in the degeneration process. The possible role played by abnormal rhodopsin metabolism in the changes observed is discussed.