title: H2 Receptor-Mediated Relaxation of Circular Smooth Muscle in Human Gastric Corpus: the Role of Nitric Oxide (NO).
abstract: This study was designed to examine the effects of histamine on gastric motility and its specific receptor in the circular smooth muscle of the human gastric corpus. Histamine mainly produced tonic relaxation in a concentration-dependent and reversible manner, although histamine enhanced contractility in a minor portion of tissues tested. Histamine-induced tonic relaxation was nerve-insensitive because pretreatment with nerve blockers cocktail (NBC) did not inhibit relaxation. Additionally, K(+) channel blockers, such as tetraethylammonium (TEA), apamin (APA), and glibenclamide (Glib), had no effect. However, N(G)-nitro-L-arginine methyl ester (L-NAME) and 1H-(1,2,4)oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), did inhibit histamine-induced tonic relaxation. In particular, histamine-induced tonic relaxation was converted to tonic contraction by pretreatment with L-NAME. Ranitidine, the H2 receptor blocker, inhibited histamine-induced tonic relaxation. These findings suggest that histamine produced relaxation in circular smooth muscle of human gastric smooth muscle through H2 receptor and NO/sGC pathways.
authors.affiliation: Department of Surgery, Konyang University Hospital, Daejeon 302-718, Korea.
authors.forename: Sang Eok
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Surgery, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Dae Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Physiology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Joung-Ho
authors.initials: JH
authors.lastname: Han
authors.affiliation: Department of Pharmacology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Woong
authors.initials: W
authors.lastname: Choi
authors.affiliation: Department of Pharmacology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Chan Hyung
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Hye Won
authors.initials: HW
authors.lastname: Jeong
authors.affiliation: Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Seon-Mee
authors.initials: SM
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Sei Jin
authors.initials: SJ
authors.lastname: Yun
authors.affiliation: Department of Pathology, Chungnam National University School of Medicine, Daejeon 305-764, Korea.
authors.forename: Song-Yi
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Pathology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Rohyun
authors.initials: R
authors.lastname: Sung
authors.affiliation: Department of Otolaryngology, Seoul National University, Borame Medical Center, Seoul 156-707, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Physiology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Ra Young
authors.initials: RY
authors.lastname: Yoo
authors.affiliation: Department of Physiology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Park Hee
authors.initials: PH
authors.lastname: Sun
authors.affiliation: Department of Preventing Medicine, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Heon
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Surgery, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Song
authors.affiliation: Department of Physiology, College of Medcine, Shanghai Jiaotong University, Shanghai 200240, P.R. China.
authors.forename: Wen-Xie
authors.initials: WX
authors.lastname: Xu
authors.affiliation: Department of Surgery, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Hyo-Yung
authors.initials: HY
authors.lastname: Yun
authors.affiliation: Department of Physiology, Chungbuk National University College of Medicine, Cheongju 361-763, Korea.
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Lee
keywords: Circular smooth muscle; Corpus; H2 receptors; Histamine; Human stomach; Nitric Oxide (NO); Relaxation