Observations on the fluorescence emitted by slices of rat liver and avian salt gland

The fluorescence emitted by slices of rat liver and sea-gull salt gland which were irradiated with light at 366 mμ, showed a peak at 468 mμ under aerobic conditions. The intensity of the fluorescence decreased during the early stages of incubation of 38°, due largely to the effects of the ultraviolet exciting radiation. Under aeobic conditions of incubation the fluorescence intensity fell by 40–60, and the remained relatively constant for a period of several hours; in anaerobic conditions the fall in intensity continued to lower levels. During the period in which the fluorescence of aerobic slices constant, quantitatively reproducible increases in tissue fluorescence were caused by the onset of tempory anoxia, by the addition of succinate to the medium and by the treatments which stimulated ion transport in the slices.