Whole kidney and cortical blood fow in rats on high and low sodium diets.

1. A method to measure total and cortical blood flow in the rat kidney has been described.2. Using this method it was found that total renal blood flow increased when rats were placed on both high and low sodium diets.3. Outer cortical blood flow in rats on a normal diet was found to be higher than the blood flow in the inner cortical region.4. The blood flow to the inner cortical region increased in rats on a low sodium diet and outer cortical blood flow did not change from normal values.5. When rats were placed on a diet high in sodium the blood flow to the outer region increased over normal values but inner cortical blood flow was not different from control values.