Effect of orthotopic small bowel transplantation on mineral metabolism in an experimental model.

Abstract

Numerous experimental models have been described for investigation of short bowel syndrome. The aim of this study was to examine the effect of orthotopic small bowel transplantation (OSBT) on universal metabolism in an inbred rat model, with particular emphasis on mineral metabolism. Jejunoileal resection and syngeneic OSBT was performed in 12-week-old male Lewis rats. Metabolic studies were performed over the following 16 weeks. Bones were analysed by physicochemical methods, dual X-ray absorptiometry, biomechanical procedures and histomorphometry. Biochemical markers of bone turnover were also measured. Jejunoileal resection induced severe short bowel syndrome with profoundly reduced food efficiency, bone size, fracturing energy and bone mineral content, but no cancellous bone osteopenia. After OSBT rats showed normal growth; bones were of normal size, and bone mineral content and fracturing energy were similar to those in sham-operated controls. However, tibial, but not vertebral, cancellous bone osteopenia was found after transplantation. OSBT with portal venous drainage achieves almost optimal mineral and bone metabolism. In the absence of immunosuppressive therapy, OSBT does not appear to have major untoward side-effects on bone in rats.