EFFECTS OF GRADED GLUTAMINE INTAKE ON LIVER PROTEIN-METABOLISM FOLLOWING PARTIAL-HEPATECTOMY

Objective: To elucidate whether glutamine can influence the rate of re generation and protein metabolism in regenerating liver. Design: Liver regeneration rate, protein content and synthesis were measured in rat s 7 days after a liver resection or sham operation. After the operatio n, the rats were fed three elementary isonitrogenous diets, one withou t and two including different levels of glutamine. Methods: Fifty-six rats were randomly assigned to either sham operation or liver resectio n. After the operation, they received an isonitrogenous, isocaloric el ementary diet with a glutamine content of 0, 2 or 4%. The resected par t of the liver was weighed and analysed for DNA and protein content. S even days later, hepatic protein synthesis was measured by the floodin g method using L-[H-3]-phenylalanine, and the liver was analysed for D NA, RNA and protein content. Results: The regeneration rate was higher in the group receiving 2% glutamine but not in the group receiving 4% glutamine than in the 0% group. Total protein content was increased i n regenerating liver in the 2 and 4% glutamine groups compared with th e 0% group. Protein synthesis was higher 7 days after liver resection than in sham-operated rats. In the 2% group, protein synthesis was mor e efficient than in the 0% group, and in the 4% group there was a tend ency towards increased protein synthesis compared with the 0% group. C onclusion: A diet with normal glutamine content improved liver regener ation rate, total protein content and protein synthesis in regeneratin g liver, but an excess of glutamine did not enhance this effect.