Light‐induced Infrared Light Scatteringsignal in the Retina: Effect of Phosphodiesterase Inhibitors

Abstract

Visible light changes IR light scatter through a toad retina. This signal presents three components: at low light intensity (100-400 bleached rhodopsins/rod) an early decrease in IR light scatter, of small amplitude, with time to peak of 1-6 s; at intermediate light intensity (1200-16,000 bleached rhodopsins/rod) a slow increase in IR light scatter, with time to peak of 10-30 s; at high light intensity (50,000-160,000 bleached rhodopsins/rod) a last increase in IR light scatter, with time to peak of 1 min. Light sensitivity, amplitude and time to peak of the last two components are increased by inhibitors (3-isobutyl-1-methyl-xanthine and papaverine) of the cyclic 3'5' guanosine monophosphate phosphodiesterase.