Glucose absorption and starch digestion in the intestine of the chicken.

Starch digestion and glucose absorption were determined in vivo along the chick's (Gallus domesticus) intestine, using 91Y and 51Cr-EDTA as unabsorbed reference substances. About 65% of the ingested starch was digested up to the end of the duodenum, 85% up to the end of the jejunum and about 97% at the terminal ileum. A fraction of about 97% of the glucose, ingested or released from ingested starch, was absorbed. The duodenum was the major site of glucose absorption which continued at a decreased rate down the small intestine. Glucose absorption increased linearily with luminal concentration with no indication of saturation. The apparent permeability for glucose was similar for the jejunum and ileum.