Water, sodium, potassium, and D-xylose absorption in canine small bowel transplantation.

Orthotopic SBT was performed in dogs according to the technique of Lillhey.1 The intestinal absorption of water. sodium (Na). potassium (K). and D-xylose by the graft (jejunal and ileal segments) was evaluated at various time periods after allotransplantation (alJotx) (n = 20; study days 3. 5. 7. and 10); alJotx treated with FK 506. 0.1 to 0.4 m,ykg per day. IV (n = 10: study days 21. :!5. and 35); autotransplantation lautotx) (n = 29: study days 7 and 14. I month. 3 months. 6 months. and 12 months); and in control nontransplanted (n = 6) animals. On the study day. jejunal and ileal segments (10 to 14 em) were isolated under Nembutal anesthesia (25 mg/kg) and perfused with a solution containing Na (120 mmoilLl. K (5 mmoi/L). and xylose (100 IL8I'mL) in water (292 mOsml at a constant rate of 1.17 mUmin over 45 minutes. The entire perfusate was collected over a IS-minute interval for a total of 45 minutes and measured for Na (flame photometryl. K (flame photometry), xylose (spectrophotometry). and water (mass balance). At the end of infusion. tissue samples were taken for histology and the animals were killed. Net absorption of Na. K. and xylose was calculated as the difference between the amount infused and the am0U:nt'recovered over 45 minutes per unit segment length. Water absorption was estimated as the difference in the volume of solution infused and the volume recovered per unit length of the segment. Statistical significance. at a P < .05. was determmed using the Kruskal-Wallis ANOV A test.