ASSESSMENT OF WATER AND SOLUTE ABSORPTION FROM EXPERIMENTAL HYPOTONIC AND ESTABLISHED ORAL REHYDRATION SOLUTIONS IN SECRETING RAT INTESTINE

Water and solute absorption from three experimental hypotonic oral rehydration solutions (HYPO-ORS; sodium 45, 60 and 75 mmol/L, glucose 90 mmol/L), the World Health Organization recommended ORS (WHO-ORS; sodium 90 mmol/L, glucose 111 mmol/L), and the British National Formulary recommended ORS (BNF-ORS; sodium 35 mmol/L, glucose 200 mmol/L), have been assessed by perfusion studies in cholera toxin-induced secreting rat intestine. Net water absorption was greatest from the most hypotonic solution (HYPO-45; P < 0.05). UK-ORS prevented net water secretion and WHO-ORS promoted moderate net water absorption. Net sodium secretion was seen with all solutions but was least from WHO-ORS and greatest with BNF-ORS (P < 0.01). Glucose absorption was similar from BNF-ORS, WHO-ORS and HYPO-45 and in each case was greater than glucose absorption from HYPO-60 and HYPO-75 (P < 0.05). These results suggest that net water and sodium absorption from ORS may be enhanced if osmolality is reduced by decreasing the glucose content.