INTESTINAL AND HEPATIC NITROGEN-BALANCE IN THE RAT AFTER THE ADMINISTRATION OF AN ORAL PROTEIN LOAD

The fate of a small oral dose of protein given to overnight-starved ra ts was studied. After 3 h, 62 % of the protein amino acids had been ab sorbed. Most of the absorbed N went into the bloodstream through the p ortal in the form of amino acids, but urea and ammonia were also prese nt. About one-quarter of all absorbed N was carried as lymph amino aci ds. The liver was able to take all portal free ammonia and a large pro portion of portal amino acids, releasing urea. The hepatic N balance w as negative, indicating active proteolysis and net loss of liver prote in.