Rabbit tissue distribution of H-3-ouabain by digital radioautography

H-3-ouabain is useful to evaluate the tissue localization of Na,K-ATPase. I n this work we determined the distribution of H-3-ouabain in rabbit tissue by digital radioautography. Using this method, we were able to obtain a com parison of various organs in a relatively short time (6.5 days), while with traditional radioautography, only the kidney was detectable after seven mo nths of film exposure. The kidney has the highest intensity (concentration of H-3-ouabain), followed by the heart, liver, muscle, lung, spleen and fin ally brain, which was almost undetectable. In kidney the activity was highe r in the cortex, while the other tissues displayed a more uniform intensity , suggesting that Na,K-ATPase was evenly distributed.