title: Electrophysiological and Mechanical Characteristics in Human Ileal Motility: Recordings of Slow Waves Conductions and Contractions, In vitro.
abstract: Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, N(W)-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Seung-Bum
authors.initials: SB
authors.lastname: Ryoo
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea. ; Department of Surgery, Seoul National University Bundang Hospital, Seongnam 13620, Korea.
authors.forename: Heung-Kwon
authors.initials: HK
authors.lastname: Oh
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Sang Hui
authors.initials: SH
authors.lastname: Moon
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea. ; Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, Seoul 06236, Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Choe
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea. ; Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Sung A
authors.initials: SA
authors.lastname: Yu
authors.affiliation: Department of Pathology, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Sung-Hye
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Kyu Joo
authors.initials: KJ
authors.lastname: Park
keywords: Human; Ileum; Motility; Slow Wave; Smooth Muscle