Water, electrolyte, glucose, and glycine absorption in rat small intestinal transplants

Water, electrolyte, glucose, and glycine absorption were studied in vivo in successful rat small intestinal transplants. Isolated bowel loops were transplanted from F1 hybrids into parental strain Lewis rats. A 7-day course of cyclosporin A was given for immunosuppression. Absorption was studied using a steady-state perfusion technique at either 9 or 21 days after transplantation. Histologic examination showed there was villus shortening with time but no evidence of rejection. When perfused with isotonic saline, both allografts and controls secreted water. However, allografts and denervated controls secreted chloride, whereas innervated controls absorbed chloride (p less than 0.05). There was a marked reduction in water and sodium absorption from 30 mM glucose-saline in transplanted loops and denervated controls, whereas glucose absorption was relatively preserved in these groups at 9 days (p less than 0.01). These changes could not be accounted for by rejection or ischemia. These studies demonstrate that denervation may be a major limiting factor in intestinal transplantation.