Intestinal absorption of naturally occurring sugars in the rainbow trout, Salmo gairdneri, under free-swimming conditions

Abstract

1. 1. An experimental procedure has been developed for measurement of intestinal nutrient absorption in the free-swimming trout. 2. 2. The surgical operation and the anesthetic (MS 222) do not affect the intestinal absorption of sugars in experiments of short (15 min) or long (90 min) duration. 3. 3. The rate of glucose absorption in μmoles/g tissue per hr from the midgut section of the digestive tract was 10·64 and from the pyloric caeca 4·14. The midgut is the region for active sugar absorption. 4. 4. At 20 mM concentration the absorption rates of glucose, galactose and mannose from the midgut were, respectively, 10·6, 6·7 and 1·9. Sugar transport mechanism of the trout has specific structural requirements.