[Electron microscopic study of 3H-leucine transport between the internal body environment and the enteral...

Using electron microscopic autoradiography, a space-time characteristics of 3H-leucine transport, from the enteral to the inner environment, and from blood plasma to the enteral environment, has been given. Some gradient of intracellular leucin accumulation is determined, from the tip cells of a villus to epithelocytes of the basal membrane. Amino acid transport from blood plasma to the lumen of the intestine is accomplished mainly via the cytoplasm and intercellular space of epithelocytes of the villus basement. It is proposed that amino acid transport through membranes of microvilli and through basal-lateral membranes of cells being on various levels along the villus may start at different amino acid concentrations which may be, presumably, to different concentration and different conjugation of enzyme-transport complexes in these membranes.