Role of large-conductance Ca2+-activated K+ channels and protein kinase G in ketamine-induced isolated tracheal smooth muscle relaxation in rats with asthma
10.3760/cma.j.issn.0254-1416.2013.03.013
- VernacularTitle:BKCa和PKG在氯胺酮舒张哮喘大鼠离体气管平滑肌中的作用
- Author:
Shuzhi ZHOU
;
Nan MA
;
Miaoling LI
;
Yan YANG
;
Xiaobin WANG
;
Jicheng WEI
- Publication Type:Journal Article
- Keywords:
Large-conductance calcium-activated potassium channels;
Protein kinases;
Ketamine;
Myocytes,smooth muscle;
Trachea;
Asthma
- From:
Chinese Journal of Anesthesiology
2013;(3):314-316
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the role of large-conductance Ga2+-activated K+ (BKCa) channels and protein kinase G (PKG) in ketamine-induced isolated tracheal smooth muscle relaxation in rats with asthma.Methods Healthy Sprague-Dawley rats,weighing 250-300 g,were used in this study.Asthma was induced with egg albumin.Thirty-six tracheal rings of 15 rats in which asthma model was successfully established were randomly divided into 3 groups (n =12 each):ketamine treatment group (group AK),IBTX (BKCa channel blocker) +ketamine treatment group (group AKI),and KT-58232 (PKG inhibitor) + ketamine treatment group (group AKK).Tracheal rings were suspended in an organ bath filled with oxygenated Kreb's solution at 36.5-37.5 ℃.In group AK,the tracheal rings were precontracted with acetyleholine 0.1 mmol/L,and the rings were then exposed to ketamine 0.4 g/L for 15 min.In group AKI,before acetyleholine and ketamine were added to the solution,the rings were pretreated with IBTX 3μmol/L for 30 min.In group AKK,before acetyleholine and ketamine were added to the solution,the rings were pretreated with KT-5823 2μmol/L for 30 min.The tension of rings was measured by using a force-displacement transducer.Results The amplitude of relaxation of isolated tracheal smooth muscle was significantly decreased in groups AKI and AKK as compared with group AK (P ＜ 0.05).Conclusion Ketamine induces isolated tracheal smooth muscle relaxation through activating BKCa channels and PKG signaling pathway in rats with asthma.
