EFFICACY OF A GLUTAMINE-BASED ORAL REHYDRATION SOLUTION ON THE ELECTROLYTE AND WATER-ABSORPTION IN A RABBIT MODEL OF SECRETORY DIARRHEA INDUCED BY CHOLERA-TOXIN

Background: Glutamine is absorbed in the intestinal tract coupled with sodium and is the principal metabolic substrate for the enterocyte. T herefore, an oral rehydration solution con taining this substance migh t provide an effective oral means of restoring electrolyte losses as w ell as speeding repair of mucosal damage. The objective of this work w as to investigate the use of an oral rehydration solution based on glu tamine in vivo in the perfused rabbit ileal loop model of secretory di arrhea induced by choleratoxin. Methods: Phenolsulfonphthalein (PSP, 5 0 mg/l) was used as a nonabsorbable marker for calculations of net wat er and electrolyte transport. Solutions tested included: (a) a glutami ne-based oral rehydration solution with 111 mmol/l glutamine, (Gln-ORS ); (b) the oral rehydration solution recommended by the World Health O rganization; (c) modified Ringer's solution. Choleratoxin (1 mu g/ml) was injected into the lumen of the ileal rabbit segments for 30 minute s prior to the initiation of the perfusion. Results: Choleratoxin indu ced significant secretion of sodium in the control modified Ringer's s olution (10.8 +/- 2.95 vs -14.05 +/- 5.95 mu Eq/g/min, n = 10; p < 0.0 1) and of water (0.06 +/- 0.03 vs -0.15 +/- 0.06 ml/g/min, n = 10; p < 0.01) with a maximum effect at 60 minutes after initiation of perfusi on. World Health Organization oral rehydration solution was able to si gnificantly reduce the intestinal secretion of sodium (control with ch olera = -14.34 +/- 2.18 vs oral rehydration solution with cholera = -0 .50 +/- 0.48 mu Eq/g/min, n = 10;p < 0.01) and water (-0.15 +/- 0.02 v s -0.012 +/- 0.005 ml/g/min, n = 10; p < 0.01). For comparison, glutam ine-based oral rehydration solution had an even greater effect on sodi um and water absorption (glutamine-based oral rehydration solution wit h choleratoxin = 10.31 +/- 1.21 mu Eq/g/min, n = 5; p < 0.01 for sodiu m and 0.08 +/- 0.008 ml water/g/min; n = 5; p < 0.01). Choleratoxin di d not change the effect of glutamine-based oral rehydration solution o n sodium and water absorption (12.90 +/- -1.09 mu Eq sodium/g/min, n = 5; and 0.11 +/- 0.01 ml water/g/min; n = 5). In addition glutamine-ba sed oral rehydration solution also induced a greater absorption of pot assium and chloride in the intestinal ileal segments treated with chol era toxin compared with World Health Organization glutamin-based oral rehydration solution. Conclusions: These results demonstrate the super ior efficacy of glutamine-based oral rehydration solution in electroly te and water absorption compared with modified Ringer's control soluti on or even with World Health Organization-recommended oral rehydration solution.