Glycogen metabolism in an amphibian retina

The rate of incorporation of [3H]glucose into glycogen was determined in bullfrog retina incubated in vitro in dark and in the light. The rate of incorporation for glucose was found to be approximately two-fold greater in the dark than in the light, 0.108 vs. 0.061 nmol mg-1 protein min-1, respectively. The turnover rate for glycogen was found also to be approximately two-fold greater in the dark than in the light, 0.051 vs. 0.027% min-1, respectively.