Abstracts
2001 Digestive Disease Week

# 337 Role of Extrinsic Innervation in Jejunal Adaptation to Total Ileal Resection
Karen D. Libsch, Nicholas J. Zyromski, Toshiyuki Tanaka, Louis J. Kost, Michael G. Sarr, Daniela Peia, Jaime Haidenberg, Mathias Worni, Rochester, MN

Segmental small bowel transplantation (SBT) offers theoretic advantages over total jejunoileal transplantation, but regional ability of the transplanted segment to adapt has not been well investigated. AIM: To investigate extrinsic neural mechanisms mediating jejunal adaptation to total ileal resection.

HYPOTHESIS: Adaptive response is blunted in denervated bowel.

METHODS: 14 dogs were implanted with cannulae in proximal jejunum to measure absorption in an 80-cm segment via a triple lumen perfusion technique. After 2 wk, separate studies measuring baseline absorption of water, electrolytes, and 4 3H-labelled nutrients (glucose, glutamine, oleic acid and taurocholic acid) were performed (2 studies per dog with each solution). Control dogs (CON, n=6) then had the distal 50% of small bowel resected, preserving ileocecal valve. Experimental dogs (EXP, n=8), underwent distal 50% enterectomy and extrinsic denervation of jejunoileum; this validated model of (auto)transplantation avoids immune rejection and ischemia/reperfusion. Absorptive studies were repeated in both groups 2 and 12 wk later.

RESULTS: All dogs developed diarrhea which resolved in all but 1 CON dog but persisted in all 8 EXP dogs. Maximal weight loss was greater in EXP (3.7±0.2 vs 2.1±0.2 kg; p<0.05). Glucose and oleate absorption was decreased at 2 wk after ileal resection in both CON and EXP; glutamine absorption was decreased at 2 wk in EXP only. All values returned to baseline at 12 wk (Table). Net fluxes of tauro-cholate and water were unchanged in both groups. Summary: Distal 50% enterectomy induces a short bowel syndrome worsened by extrinsic denervation. Despite more weight loss and persistent diarrhea, there were no differences in absorptive fluxes 12 wk after denervation.

CONCLUSION: Extrinsic denervation as necessitated by SBT does not blunt the jejunal adaptive response to total ileal resection. (Support NIH R01 DK39337-MGS)

Glucose Glutamine Oleic acid

CON EXP CON EXP CON EXP

Baseline 4.2±0.5 4.0±0.4 4.0±0.4 4.1±0.2 9.7±1.0 9.2±0.5

2 wk 2.7±0.6* 2.5±0.8* 3.5±0.7 2.6±0.4* 6.3±0.5* 5.8±0.8*

12 2k 3.7±0.3 4.0±1.1 4.4±1.0 3.6±0.6 8.0±1.6 7.5±1.5

Absorptive fluxes (mM cm^-1 10^-2) are x±SEM, *p<0.05 vs baseline.