EFFECT OF LIGHT ON GANGLIOSIDES FROM CALF RETINA AND PHOTORECEPTORS

Abstract

Abstract —The gangliosides of the whole calf retina and the rod outer segments have been analysed. This has been done in two functional states: before and after stimulation by light. After exposure to light no statistically significant change in the gangliosides of the whole retina was observed, but a 40 per cent increase in concentration was found in the rod outer segments. This difference was apparent only when using the same batch of rod outer segments. The major ganglioside in the whole calf retina is G D3 which accounts for 46 per cent of the total. Three other gangliosides G D1a , G D1b and G T1 are quantitatively important, each being between 12 and 16 per cent. G Q1 , G M1 , and G M3 are minor constituents. In contrast to the chicken retina, G M2 was not detected. The ganglioside N ‐acetylneuraminic acid of the rod outer segments accounts for only 1 per cent of the gangliosides of the whole retina. The composition of the gangliosides in the rod outer segments is essentially the same as that of the whole retina. No difference in the relative proportion of the gangliosides of either the rod outer segments or the whole retina was observed after exposure to light.