[Assimilation of free and peptide glycine in the chick small intestine].

Absorption of free and peptide glycine released at the hydrolysis of glycyl-L-leucine, L-leucyl-glycine, glycyl-L-valine was investigated in experiments in vitro with accumulating mucosal preparations of the chick small intestine. An active accumulation of free amino acid occurred in the mucosa depending on sodium and oxygen presence in the incubation medium. The participation of sodium-dependent and sodium-independent components in the transport was revealed. Absorption of peptide glycine released at the hydrolysis of glycyl-L-leucine and glycyl-L-valine appeared to be a sodium-independent process and demanded the energy of aerobic metabolism. The data indicate the effect of various amino acids on the transport of free and peptide glycine. Activating effect of some of them on the absorption of glycine is supposed to be determined for this amino acid by a mechanism of exchange transport in the chick small intestine.