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 implicated in the pathogenesis of protracted diarrhoeal disease in infancy. Vitamin E deficiency is common in malnourished infants with protracted diarrhoea. We have studied the effects of chronic vitamin E deficiency on small-intestinal secretion and absorption in the rat. 2. Weanling rats were fed vitamin E-sufficient or -deficient diets for 21 weeks. Jejunal function was studied in vitro in an Ussing chamber after this period. 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. Basal intestinal short-circuit current was the same in both groups. 5. Cyclic nucleotide and maximal non-neuronal acetylcholine-mediated electrogenic secretion were increased in vitamin E-deficient jejuna. 6. Exogenous 5-hydroxytryptamine (serotonin) induced a smaller increment in electrogenic secretion in vitamin E-deficient jejuna. 7. Vitamin E-deficient jejuna were less responsive to exogenous noradrenaline, resulting in a smaller alpha 2-adrenergic-mediated decrease in intestinal short-circuit current. 8. Fasting for 72h produced a greater increment in intestinal short-circuit current in vitamin E-deficient jejuna. 9. Chronic vitamin E deficiency is prosecretory in the small intestine and may predispose to the perpetuation of protracted diarrhoeal diseases.