A comparison on natriuresis after oral and intravenous sodium loading in sodium-depleted rabbits: evidence for a gastrointestinal or portal monitor of sodium intake.

1. Rabbits in balance on a low sodium diet were given doses of sodium chloride either orally or intravenously. 2. Those receiving oral doses responded with a much greater natriuresis than those receiving intravenous ones. 3. This could be explained by the existence of a sodium input monitor somewhere in the gut or portal circulation.