The effects of severe zinc deficiency on intestinal amino acid losses in the rat

To determine whether intestinal amino acid losses might occur during zinc deficiency, labeled aminoisobutyric acid was given parenterally to zinc deficient rats and to appropriate zinc-sufficient controls. After 24 hours, the aminoisobutyric acid loss into the intestinal lumen was measured by in situ perfusion of isolated intestinal segments under conditions of either net water absorption or water secretion. Net amino acid losses were larger in the jejunum of the zinc deficient rats and losses were exacerbated during net water secretion in the jejunum and colon segments. The contribution of amino acid losses to fecal nitrogen, particularly during osmotic diarrhea, may be important in the growth retardation of zinc deficiency. Further, these alterations may indicate defective enterocyte transport functions during severe deficiency.