Acta Physaol Scand zyxwvutsrq 1993, 149, 525-526 zyxwvu Duodenal drainage reduces cycling frequency of the migrating motor complex in humans 1. NILSSON,' T. SVENBERG' and P. M. HELLSTROM' zyxw ' Department of Surgery and Section for Gastroenterology, Department of Medicine, Karolinska Hospital, Stockholm, Sweden Interdigestive motility of the proximal gastrointestinal tract is co-ordinated with gastric duodenal and pancreatico-biliary output (Vantrappen et zyxwvuts al. 1979b, Keane et a/. 1980, Nilsson et al. 1990). In previous studies in humans we have found that bile flow into the duodenum stimulates release of the gut peptide motilin to the circulation (Svenberg et al. 1984, Nilsson et al. 1993). Motilin has been considered to play a physiological role in the initiation of phase 3 of the migrating motor complex (MMC) in humans, since intravenous infusion of motilin induces premature phase 3, and peak values of plasma motilin precede duodenal phase 3 by about 15min (Vantrappen et al. 1979a). Further, interdigestive emptying of the gallbladder, motilin release and the onset of phase 3 of MMC are temporally co-ordinated events (Nilsson et al. 1990). Experimental studies in the rat have shown that drainage of bile changes the motility pattern from MMC to continuous irregular spiking, and that luminal infusion of bile acids reinstates the M M C pattern (Nilsson et al. 1991). The aim of our study was therefore to determine if duodenal drainage affects the recycling pattern of MMC in man. Experiments were carried out twice in each of six healthy male volunteers (23-37 years) after an overnight fast. The first experimental session was performed without duodenal drainage, whereas the second session included duodenal drainage. Using fluoroscopy,a multichannel polypropylene manometry catheter (William Cook, Copenhagen, Denmark) was passed to the duodenum. Four channels with side- holes 5 cm apart were perfused constantly with distilled water and connected to external pressure transducers (Druck Ltd, Leicester, UK). Pressure changes in the duodenum were registered on a multi- Received 14 September 1993, accepted 14 Sep- tember 1993. Key words : interdigestive motility, migrating motor complex, motility, pancreatico-biliary output, small intestine. Correspondence : 1. Nilsson, Department of Sur- gery, Karolinska Hospital, S-171 76 Stockholm, Sweden. channel ink-jet recorder (Siemens-Elema, Stockholm, Sweden). In addition, a marker solution containing polyethylene glycol (PEG 4000, Kebo, Stockholm, Sweden) diluted in saline to a final concentration of 10 g I-' was perfused at a rate of 1 ml min-' through z 'a. separate channel in the manometry catheter ending 10 t m proximal to the first manometry recording site. A Ryles tube (FG 10; Portex, Hythe, UK) ending 10 cm distal to the perfusion site was attached to the manometry catheter for drainage zyx of duodenal contents. T h e pressure recordings were analysed as follows at the level of the ligament of Treitz: phase 1 of MMC was defined as 6 two contractions per 10 min, phase 2 as between three and 10 contractions per 10 min, and phase 3 as an aborally migrating burst of uninterrupted contractions at a frequency of 11-12 per min followed by a period of complete quiescence. Each phase 3 of MMC was analysed with regard to its duration, contraction frequency and propagation velocity. In experiments with duodenal drainage, contents were continuously siphonaged through the Ryles tube. Duodenal contents were analysed for concen- trations of PEG and total bile acids. The duodenal flow was calculated from the dilution of PEG. The output of bile acids was calculated multiplying concentrations by duodenal flow. The duodenal flow 1 $ zyxw 0.75 3 0 0.5 n c 0.25 a 0 T * I No duodenal drainage Duodenal drainage Fig. 1. Frequency of phase 3 of MMC in experiments without and with partial drainage of duodenal contents. 525