Flux and turnover rates of glycine in the dog liver perfused in situ

¹ Departments of Biological Chemistry and Surgery, Harvard Medical School, Boston, Massachusetts; and the Department of Surgical Research, Michael Reese Hospital and Medical Center, Chicago, Illinois
² Department of Biological Chemistry and Surgery, Harvard Medical School, Boston, Massachusetts; and the Department of Surgical Research, Michael Reese Hospital and Medical Center, Chicago, Illinois

Distribution of added glycine-1-C¹⁴ in the perfused dog liver was studied. Concentrations and specific activities of glycine in liver and plasma were measured as a function of time. Calculated values for glycine fluxes between plasma and liver were for influx, 10 to 150, efflux, 10 to 90, and for net influx into liver, –10 to 80 µmole/min/kg liver. Administration of an amino acid mixture containing unlabeled glycine increased the rates of influx, efflux and net flux of glycine into the liver, as well as the concentration of glycine in plasma. The turnover rate of glycine in liver was found to be of the order of 400 µmole/min/kg liver. The specific activities of other amino acids, glucose, and glycogen were measured.

Note:
With the Technical Assistance of Florinell M. Washington