Intestinal absorption of hexoses in the dog

¹ Department of Physiology, Northwestern University Medical School, Chicago, Illinois

Solutions (310 mosmoles/liter) containing NaCl and 14–280 mm/liter hexose were perfused through jejunal or ileal fistulas in unanesthetized dogs. Each hexose was given alone and in combination with several concentrations of another hexose. Glucose, galactose, and fructose absorption rates increased in nearly hyperbolic fashion with increasing lumen concentrations whereas the absorption rate for sorbose was nearly directly proportional to its concentration in both jejunal and ileal loops. The perfusate hexose concentration for one-half maximal absorption rate differed between glucose, galactose, and fructose although all three sugars approached a similar maximum absorption rate. When pairs of hexoses were perfused, glucose and galactose seemed to compete for absorption whereas glucose and fructose, galactose and fructose, glucose and sorbose, and galactose and sorbose were absorbed nearly independently.

Key Words: glucose absorption • galactose absorption • fructose absorption • sorbose absorption • competitive hexose absorption • independent hexose absorption

Submitted on June 28, 1963