Glucose rehydration therapy
The movement of Na+ and glucose from the lumen of the intestine across the epithelial cell to the blood sets up a difference in osmotic pressure across the cell. As per the result, water flows by the cell, across the apical and basolateral membranes by simple diffusion. Therefore the uptake of water needs both Na+ and glucose (or amino acids) to be present in the lumen of the intestine. The occurrence of water alone in the lumen of the intestine is much less effective. That is the basis of glucose rehydration therapy as a remedy for dehydration; a solution of glucose and salt (NaCl) is administered to the patient. This is a simple inexpensive but very extremely important treatment that has saved the lives of many infants in developing countries who would have otherwise died of the effects of dehydration, generally associated with diarrhea.