MODULATION OF SMALL-INTESTINAL SECRETION AND ABSORPTION IN CHRONIC VITAMIN-E-DEFICIENCY - STUDIES IN RAT JEJUNUM IN-VITRO

1. A vicious cycle of malabsorption and malnutrition has been implicat ed in the pathogenesis of protracted diarrhoeal disease in infancy. Vi tamin E deficiency is common in malnourished infants with protracted d iarrhoea. We have studied the effects of chronic vitamin E deficiency on small-inestinal secretion and absorption in the rat. 2. Weanling ra ts were fed vitamin E-sufficient or -deficient diets for 21 weeks. Jej unal function was studied in vitro in an Ussing chamber after this per iod. 3. Steady-state isotopic flux experiments in unstimulated tissues demonstrated net Na+ and Cl- secretion in vitamin E-deficient jejuna but net Na+ and Cl- absorption in vitamin E-sufficient jejuna. 4. Basa l intestinal short-circuit current was the same in both groups. 5. Cyc lic nucleotide and maximal non-neuronal acetylcholine-mediated electro genic secretion were increased in vitamin E-deficient jejuna. 6. Exoge nous 5-hydroxytryptamine (serotonin) induced a smaller increment in el ectrogenic secretion in vitamin E-deficient jejuna. 7. Vitamin E-defic ient jejuna were less responsive to exogenous noradrenaline, resulting in a smaller alpha2-adrenergic-mediated decrease in intestinal short- circuit current. 8. Fasting for 72 h produced a greater increment in i ntestinal short-circuit current in vitamin E-deficient jejuna. 9. Chro nic vitamin E deficiency is prosecretory in the small intestine and ma y predispose to the perpetuation of protracted diarrhoeal diseases.