Abstracts
2000 Digestive Disease Week

# 2330 Selective Role of Vagal and Non-Vagal Innervation in Control of Migrating Motor Complex (MMC) and Postprandial Motility.
Toshiyuki Tanaka, Luke H. Vanklompenberg, Michael G. Sarr, Rochester, MN

Multivisceral upper gut transplantation is now reality, but motility in the graft is poorly understood. AIM: To determine the role of vagal and extravagal innervation in control (initiation, coordination, timing) of fasting and fed motility. HYPOTHESIS: Vagal and non-vagal extrinsic nerves are not necessary for normal fasting or fed motor patterns. METHODS: 3 dogs underwent a model of staged multivisceral upper gut autotransplantation. All continuity (neural, lymphatic and all other connective tissue) between the upper gut complex consisting of stomach, small bowel, proximal colon, liver and pancreas was transected except for the walls of celiac and superior mesenteric arteries and suprahepatic and infrahepatic vena cava stripped of adventitia. Vagal nerves to stomach were preserved (Stage 1) (confirmed by Hollander test). Esophagus and distal colon were transected and reanastomosed. Gastroduodenal transection/ reanastomosis was also performed to disrupt neural continuity between stomach and duodenum thus fully neurally isolating the stomach. Manometry catheters were implanted in antrum and small bowel; dogs were studied on =4 occasions during fasting and on 2 occasions each after small (50 g) and large (200 g) liver meals before (Stage 1) and after transthoracic abdominal vagotomy (Stage 2). Characteristics of the MMC and its postprandial inhibition were determined. Data are mean±SEM. RESULTS: A characteristic MMC persisted after both Stages 1 and 2. The gastric MMC remained coordinated with duodenal MMC despite lack of extrinsic or intrinsic neural continuity. No differences were noted in durations (min) of the MMC (128±18 vs 137±7), the 4 phases of MMC (data not shown) and postprandial inhibition after small meal (157±9 vs 164±19) or large meal (312±32 vs 338±55) (p>0.05). Vagotomy, however, altered the pattern of gastric contractions during phase III by changing number of contractions (48±7 vs 17±2), duration between groupings of contractions (1±0 vs 3±0 min), and motility index (12±0 vs 10±0)(p<0.05 each). SUMMARY: A cyclic fasting motility and gastroduodenal coordination persisted and was inhibited by feeding after staged extrinsic denervation of the upper gut. CONCLUSIONS: Neither non-vagal nor vagal innervation is needed to initiate or coordinate fasting and fed motility, but vagal nerves modulate contractile patterns during phase III. The denervation of multivisceral gut transplantation does not disrupt normal GI motor patterns. (Support: NIH DK39337)