Developmental study of alpha-methyl-D-glucoside and L-proline uptake in the small intestine of the White Leghorn chicken.

Development changes in alpha-methyl-D-glucoside and L-proline accumulation were studied using everted sleeves from the duodenum, jejunum, and ileum of chickens. Six age groups of chickens were used: 1 d and 1, 2, 3, 5 to 6, and 12 to 14 wk. Our results showed the presence of a Na+-dependent mechanism of sugar and amino acid uptake that is already fully developed at hatch. The intestinal transport activity undergoes substantial changes with age and region studied. Intracellular accumulation of alpha-methyl-D-glucoside and L-proline was greater in newly hatched chicks and then declined with age in the three regions of the small intestine, except for L-proline transport in ileum, which remained constant during the period studied. The transport mechanisms for each nutrient followed separate developmental patterns along the small intestine during the period studied.