EFFECTS OF MALNUTRITION, AGE, AND CHOLERA TOXIN ON GLUCOSE-STIMULATED WATER ABSORPTION

Abstract

Oral administration of glucose-containing solutions reduces net stool output in patients with cholera. Since malnutrition is frequently associated with diarrhea, we examined the influence of malnutrition on intestinal response to glucose in experimental cholera. Water fluxes (Jv) were determined by weighing intestinal fluid at different times in isolated ligated loops of jejunum. The effects on Jv of glucose and mannitol (30mM + Ringer) were compared in loops with and without (C) cholera toxin (CT), in 20 adult control rats, 20 adult rats with protein caloric malnutrition (PCM), 10 adult rats on a protein-free diet (APM), and 10 growing rats on a protein-free diet (YPM). Glucose stimulated water absorption (expressed in μ1/10 min cm2) equally in control loops and in CT loops in all four groups studied. The C and CT values for Jv were respectively 36.2 ± 7.5 and 39.6 ± 11.9 in control rats, 64.4 ± 8.3 and 73.8 ± 10 in PCM, 37.1 ± 8.1 and 41 ± 5.2 in APM, and 18.9 ± 3.5 and 18.1 ± 2.6 in (YPM). Similarly, CT did not modify the fluxes of Na, C1, HCO3 and glucose. The relationship between Jv, JNa and Jglucose remained unchanged. The effect of glucose on water fluxes in intestine was therefore not influenced by cholera toxin, but greatly depended on the type of malnutrition and on the age of the rats. In addition, the present results suggest that the intestinal secretion induced by cholera toxin is independent of the intestinal absorption stimulated by glucose.