CREATINE IN DARK AND ILLUMINATED RETINAE

Abstract

1. The contents of free and bound creatine in the extracts of light and dark adapted retinae of toads were estimated by means of Jaffe's reaction and of a photoelectric spectrophotometer.
2. The total amounts of free creatine in the extract of 40 retinae illuminated and dark adapted were 73γ and 56γ respectively while the amounts of creatine originating from the phosphocreatine in the same extract were 7γ and γ respectively.
3. These results together with the previous observation on the inhibitory effects of creatine on the regeneration of visual purple, lead us to conclude that the breakdown and resynthesis of phosphocreatine are directly related with the photochemical changes of the visual purple.