Different effects of smoke from heavy and light cigarettes on the induction of bronchial smooth muscle hyperresponsiveness in rats
スポンサーリンク
概要
- 論文の詳細を見る
Cigarette smoking is one of the main risk factors in the development of chronic obstructive pulmonary disease (COPD). It has been suggested that an augmented agonist-induced, RhoA mediated Ca2+ sensitization is responsible for the enhanced bronchial smooth muscle contraction induced by cigarette smoking. In the present study, to determine whether or not these phenomena are dependent on the degree of exposure to the components of cigarette smoke, we examined the effects of exposure to mainstream smoke derived from either light or heavy cigarettes on both the contractile responsiveness and the expression of RhoA in bronchial smooth muscle. Male Wistar rats were exposed to mainstream cigarette smoke for 2 hr/day for 2 weeks. Twenty-four hr after the last cigarette smoke exposure, we measured isometrical contractions of the bronchial smooth muscle. The concentration-response curve to ACh was significantly shifted upward after heavy cigarette smoke (HCS) exposure, whereas no significant difference was observed in the case of light cigarette smoke (LCS) exposure compared with control rats. No significant difference in K+ responsiveness was observed between the groups. The expression of RhoA protein in bronchial preparations from rats repeatedly exposed to HCS, but not to LCS, was significantly increased as compared with that of the control animals. On the other hand, inhalation of nicotine had no effect on either the ACh- and high K+ depolarization-induced contractions or the expression of RhoA protein. The increased expression of RhoA seems to have an important role in the augmented contractile responses of the airways in rats, a characteristic feature of early COPD.
論文 | ランダム
- トップレポート 3月危機のハードルは越えたが 金融行政の先送り体質に変化なし
- 航空機MSSで砺波平野の季節変化を捉える : 潅水期と夏期における昼と夜の表面温度分布
- 40286 航空機MSSデータを用いた砺波平野における潅水期の水田表面温度の解析(リモートセンシング,環境工学I)
- NEOCARZINOSTATINの宿主免疫能への影響に関する基礎的研究 第二編 細胞性免疫能への影響に関する検討
- NEOCARZINOSTATINの宿主免疫能への影響に関する基礎的研究 第一編 体液性免疫能への影響に関する検討