title: Tetrandrine ameliorates ischaemia-reperfusion injury of rat myocardium through inhibition of neutrophil priming and activation.
abstract: 1. We have previously shown that tetrandrine (TTD), a bisbenzyltetrahydroiosquinoline isolated from the Chinese herb Stephania tetrandra, inhibits neutrophil adhesion, Mac-1 expression, and reactive oxygen species (ROS) production. To examine whether inhibition of neutrophil function may confer upon TTD the ability to prevent myocardial ischaemia-reperfusion (MI/R) injury, experiments were performed on rats subjected to coronary ligation followed by reperfusion for induction of MI/R injury. 2. Intravenous administration of TTD (0.1 and 1.0 mg kg-1) 15 min prior to coronary ligation completely prevented MI/R-associated mortality. TTD pretreatment also significantly reduced MI/R-induced ventricular tachyarrhythmia, myocardial infarct size, and neutrophil infiltration. 3. However, TTD pretreatment did not influence mean arterial blood pressure, heart rate, or product of pressure-rate, indicating that TTD extenuated MI/R through mechanisms independent of modulating haemodynamics or myocardial oxygen demand. 4. Peripheral blood neutrophils were isolated for ex vivo examination of shape change and Mac-1 upregulation of neutrophils, two sensitive indicators of proinflammatory priming, as well as N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced adhesion and ROS production, parameters commonly used for the assessment of neutrophil activation. 5. Neutrophils from MI/R animals showed significant shape change and Mac-1 upregulation, both of which were prevented by TTD-pretreatments. On the other hand, fMLP-induced adhesion and ROS production of neutrophils were markedly enhanced by MI/R but diminished in TTD-pretreated animals. 6. These data suggest that the protective effect of TTD against MI/R injury can be accounted for by inhibition of neutrophil priming and activation, thereby abolishing subsequent infiltration and ROS production that cause MI/R injury.
authors.affiliation: National Research Institute of Chinese Medicine, 155-1 Section 2, Li-Nung Street, Shih-Pai, Taipei 112, Taiwan.
authors.forename: Y C
authors.initials: YC
authors.lastname: Shen
authors.forename: C F
authors.initials: CF
authors.lastname: Chen
authors.forename: Y J
authors.initials: YJ
authors.lastname: Sung
mesh_terms: D000470:Alkaloids / Q000627:therapeutic use*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000401:mortality / Q000517:prevention & control; D044182:Benzylisoquinolines; D001794:Blood Pressure / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects; D016177:Macrophage-1 Antigen / Q000096:biosynthesis; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology / Q000517:prevention & control; D017202:Myocardial Ischemia / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D018375:Neutrophil Activation / Q000187:drug effects*; D020556:Neutrophil Infiltration / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000470:Alkaloids; D000889:Anti-Arrhythmia Agents; D044182:Benzylisoquinolines; D016177:Macrophage-1 Antigen; D017382:Reactive Oxygen Species; C009438:tetrandrine