FAT-STIMULATED CHOLECYSTOKININ RELEASE FOLLOWING TRANSPLANTATION OF THE ENTIRE SMALL-BOWEL OR OF DIFFERENT INTESTINAL SEGMENTS IN RATS

This study presents data on the fat-stimulated release of cholecystoki nin (CCK) in conscious rats 11 and 84 days after one-stage transplanta tion of the entire small bowel, or of jejunal, jejunoileal, or ileal s egments, under syngeneic and allogeneic conditions. After allotranspla ntation, ciclosporin (CsA) was administered for graft acceptance. The results were compared with those in unoperated controls and in animals that had undergone small-bowel resections leaving jejunal, jejunoilea l, or ileal remnants. When the entire small bowel was grafted under sy ngeneic (92.5 +/- 8.3; 106.6 +/- 7.5) or allogeneic (110.5 +/- 5.5; 10 1.2 +/- 6.9) conditions, CCK release (pg/ml per 60 min) was similar (P >0.05) to that of the controls (110.3 +/- 9.0; 94.7 +/- 6.8) at both m easurement points. Recipients of jejeunal or ileal segmental isografts showed a significantly elevated (P < 0.05) output of CCK (jejunal gra ft: 176.4 +/- 18.5; 125.5 +/- 10.1 - ileal graft: 55.9 +/- 9.0; 30.1 /- 5.4) compared with corresponding small-bowel resections (jejunal re mnant: 69.0 +/- 7.9; 93.5 +/- 3.9 - ileal remnant: 16.7 +/- 3.7; 6.6 /- 1.3). In contrast, the difference was not significant (P > 0.05) wh en jejunoileal segments were grafted (jejunoileal graft: 74.4 +/- 19.6 ; 47.0 +/- 10.4 -jejunoileal remnant: 50.7 +/- 11.0; 47.0 +/- 11.9). A ll recipients of jejunal allografts died between day 8 and day 10 afte r transplantation, due to functional impairment. Two-stage segmental j ejunal allotransplantation, with insertion of the graft into the conti nuation of the gastrointestinal tract in an accessory, non-functional position after 28 days was successful. Due to this technique, we could gather data on day 84. Recipients of jejunal (118.2 +/- 7.6), jejunoi leal (87.1 +/- 19.7; 48.6 +/- 9.3), or ileal (48.1 +/- 6.7; 21.6 +/- 4 .6) allografts showed no significant (P > 0.05) differences in CCK out put compared with isografts, either on day 11 or on day 84. Our data i ndicate that transplantation of the entire small bowel affects the fat -stimulated CCK release neither in the early postoperative period nor 3 months after transplantation. In contrast, transplantation of jejuna l or ileal segmental isogorafts caused a significantly elevated output of CCK compared with corresponding resection remnants. Immunosuppress ion with CsA did not affect CCK release after transplantation, but led to functional impairment with fatal outcome when a short jejunal segm ent was grafted. This could be prevented by applying the two-stage tec hnique.