Plasma citrulline, ornithine, and arginine concentrations at the end of the enteral nutrition programme. Four groups of rats were studied: sham (transected rats fed standard enteral nutrition), control (resected rats fed standard enteral nutrition), arginine (Arg; resected rats fed arginine supplemented diet), citrulline (Cit; resected rats fed citrulline supplemented diet). Results are expressed as mean values (SEM). Values with different superscript letters are statistically different.