[The effect of aging on intestinal absorption]

The author collected datas on the field of the absorption of d-glucose and various amino acids (gly, l-ala, l-val, l-thr, l-leu, l-phe, l-try, l-pro, l-his, l-lys and l-arg) in rats of different ages. On the basis of "in vivo' experiments and kineticale approaches, it became evident that older the organism, the smaller the affinity of the hexosecarrier for the glucose molecules. It means that the sugar will be transported at a higher (faster) rate in the young rat at a relatively low (initial) luminal concentrations than in the old. Similarly, the young organism through its regulation mechanisms coordinates the components of the intermediate amino acid metabolism to such a degree to keep the faster transport at a lower luminal concentrations. In the old, there might be several enzyme disorders, maldigestions/malfunctions. These may result lowered sugar and amino acid concentrations in the lumen. Generally, it draws a slower resorption rate which possibly leads to the maintenance of an optimal amino acid flux essentially needed by homeostasis.