title: Augmented bronchial smooth muscle contractility induced by aqueous cigarette smoke extract in rats.
abstract: Cigarette smoking is the main risk factor for the development of chronic obstructive pulmonary disease (COPD). However, little is known about the mechanisms of cigarette smoke-induced bronchial smooth muscle (BSM) hyperresponsiveness. In the present study, we investigated the effects of aqueous cigarette smoke extract (ACSE) on the BSM contraction in rats. The bronchial strips of rats were incubated with ACSE or control-extract for 24 h. The acetylcholine (ACh), high K(+) depolarization and sodium fluoride (NaF)-induced BSM contraction of the ACSE-treated group was significantly augmented as compared to that of the control one. The expression levels of both myosin light-chain kinase (MLCK) and RhoA were significantly increased in the ACSE-treated BSM. These findings suggest that the water-soluble components of cigarette smoke may cause BSM hyperresponsiveness via an increase in MLCK and RhoA.
authors.affiliation: Department of Pharmacology, Hoshi University, Tokyo, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Sakai
authors.forename: Ayako
authors.initials: A
authors.lastname: Watanabe
authors.forename: Akiko
authors.initials: A
authors.lastname: Fujita
authors.forename: Miwa
authors.initials: M
authors.lastname: Misawa
authors.forename: Minoru
authors.initials: M
authors.lastname: Narita
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Chiba
mesh_terms: D000818:Animals; D001980:Bronchi / Q000187:drug effects*; D016535:Bronchial Hyperreactivity / Q000209:etiology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D010936:Plant Extracts / Q000009:adverse effects*; D017208:Rats, Wistar; D012907:Smoking / Q000009:adverse effects*; D014026:Nicotiana / Q000737:chemistry*; D014867:Water; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D010936:Plant Extracts; D014867:Water; D009219:Myosin-Light-Chain Kinase; D020742:rhoA GTP-Binding Protein