Kinetics of glycylsarcosine transport by isolated chicken intestinal epithelial cells.

Kinetics of Glycylsarcosine (Gly-Sar) uptake by isolated chicken enterocytes was studied by measuring its intracellular concentration, and by discriminating between the saturable and the diffusive components of the total uptake. The diffusive component was greater at pH 6.0 than at pH 7.4, and the J max was also increased by lowering external pH, whereas the Km remained in the same order of magnitude. Carnosine competitively inhibits Gly-Sar uptake, indicating that both share a common transport system.