Neurohumoral mechanism involved in augmentation of canine jejunal absorption following oral rehydration solutions

Throughout the world diarrheal diseases kill over 5 million children annually. Oral rehydration therapy, initially using glucose-based solutions and more recently cereal-based solutions, prevents complications and death from dehydration. These experiments compared the effect of these two rehydration solutions and a mixed meal on jejunal water and ionic transport. Five dogs had 25-cm proximal jejunal Thiry-Vella fistulae constructed. Following recovery, jejunal absorption studies (N=40) were performed using an isotonic electrolyte solution containing [¹⁴C]PEG to calculate net fluxes of water, sodium, and chloride. Each study consisted of a 1-hr basal period, followed by a 3-hr experimental period. Each animal was randomly studied in each of four study groups: control, mixed meal, glucose-based and cereal-based rehydration solution. In the mixed meal, glucose-based, and cereal-based solution groups there were significant increases (P<0.0001) in jejunal Thiry-Vella fistula water and ion absorption following the stimuli, in the absence of direct luminal nutrient contact with the Thiry-Vella fistula. There were no differences between the observed responses to the glucose-based or cereal-based rehydration solutions. Glucose-based and cereal-based rehydration solutions were equally effective in stimulating jejunal absorption of water and electrolytes, but less effective than a mixed meal. Both food and oral rehydration solutions appear to increase jejunal absorption partially via a neurohumoral mechanism that is independent of luminal nutrient contact with the Thiry-Vella fistula.