stilbenes and Tachycardia--Ventricular

The effects of resveratrol treatment on ventricular arrhythmia, survival, and late cardiac remodeling were evaluated in rats with myocardial infarction (MI).. Three groups of rats (S: ham-operated, MI, and MI pre-treated with resveratrol) were treated in an in vivo MI model by ligation of left anterior descending coronary artery. The electrocardiogram signals were monitored and recorded for 24 h using an implanted telemetry transmitter. The incidence of ventricular arrhythmias during the first 24-h after MI was also evaluated. Meanwhile, invasive in vivo electrophysiology with pacing in the right ventricle was performed in each group to assess the inducibility of ventricular arrhythmias.. Administration of resveratrol significantly suppressed the MI-induced ventricular tachycardia and ventricular fibrillation (0.4 +/- 0.2 in Resv group vs. 7.1 +/- 2.2 in MI group episodes per hour per rat, P < 0.01). Data also showed that the incidence of inducible ventricular tachycardia was lower in the Resv group than the MI group (46% vs. 81%, P < 0.01). The infarct size and mortality in the Resv group at 14 weeks were reduced by 20% and 33%, respectively, compared with the MI groups. Results from patch clamp recording revealed that resveratrol inhibited L-type calcium current (I (Ca-L)), and selectively enhanced ATP-sensitive K(+) current (I (K,ATP)) in a concentration-dependent manner.. These results suggested that the emerging anti-arrhythmic character induced by resveratrol treatment in rat hearts could be mainly accounted for by inhibition of I (Ca-L) and enhancement of I (K,ATP). Administration of resveratrol also improved the long-term survival by suppressing left ventricular remodeling.

Topics: Administration, Oral; Animals; Calcium Channels, L-Type; Cardiac Pacing, Artificial; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Electrocardiography; KATP Channels; Male; Myocardial Infarction; Patch-Clamp Techniques; Phytoalexins; Prostheses and Implants; Rats; Rats, Sprague-Dawley; Resveratrol; Sesquiterpenes; Stilbenes; Survival Rate; Tachycardia, Ventricular; Telemetry; Terpenes; Time Factors; Ventricular Fibrillation; Ventricular Remodeling

Oxidative stress plays an important role in the pathogenesis of myocardial ischemia and infarction. Antioxidants might then be beneficial in the prevention of these diseases. Astringinin (3,3',4',5-tetrahydroxystilbene), a resveratrol (3,4',5-trihydroxystilbene) analogue with considerably higher antioxidative activity and free radical scavenging capacity, was introduced to examine its cardioprotective effects in ischemia or ischemia-reperfusion (I/R) rats. In the present study, the left main coronary artery was occluded by the following procedures: (i) 30 min occlusion, (ii) 5 min occlusion followed by 30 min reperfusion, and (iii) 4 h occlusion. Animals were infused with and without astringinin before coronary artery occlusion. Mortality, and the severity of ischemia- and I/R-induced arrhythmias were compared. Pretreatment of astringinin dramatically reduced the incidence and duration of ventricular tachycardia (VT) and ventricular fibrillation (VF) during either ischemia or I/R period. Astringinin at 2.5 x 10(-5) and 2.5 x 10(-4) g/kg completely prevented the mortality of animals during ischemia or I/R. During the same period, astringinin pretreatment also increased nitric oxide (NO) and decreased lactate dehydrogenase (LDH) levels in the carotid blood. In animals subjected to 4 h coronary occlusion, the cardiac infarct size (expressed as a percentage of occluded zone) was reduced from 44.4 + or - 4.1% to 19.1 + or - 2.4% by astringinin (2.5 x 10(-4) g/kg). We conclude that, astringinin is a potent antiarrhythmic agent with cardioprotective activity in ischemic and ischemic-reperfused rat heart. The beneficial effects of astringinin in the ischemic and ischemic-reperfused hearts may be correlated with its antioxidant activity and upregulation of NO production.

Topics: Animals; Antioxidants; Free Radical Scavengers; Heart; Hemodynamics; L-Lactate Dehydrogenase; Male; Myocardial Infarction; Myocardial Reperfusion Injury; Nitrates; Nitric Oxide; Nitrites; Rats; Resveratrol; Stilbenes; Tachycardia, Ventricular; Ventricular Fibrillation

The major objective of the present study was to examine the cardioprotective effect of resveratrol, an antioxidant presents in red wines, in the rat after ischemia and ischemia-reperfusion (I-R).. The left main coronary artery was occluded for 30 or 5 min followed by a 30-min reperfusion in anesthetized rats. Animals were preinfused with and without resveratrol before occlusion and the severity of ischemia- and I-R-induced arrhythmias and mortality were compared.. Resveratrol pretreatment had no effect on ischemia-induced arrhythmias nor on mortality. In contrast, a dramatic protective effects were observed against I-R-induced arrhythmias and mortality. Resveratrol pretreatment both reduced the incidence and duration of ventricular tachycardia (VT) and ventricular fibrillation (VF). During the same period, resveratrol pretreatment also increased nitric oxide (NO) and decreased lactate dehydrogenase levels in the carotid blood.. Resveratrol is a potent antiarrhythmic agent with cardioprotective properties in I-R rats. The cardioprotective effects of resveratrol in the I-R rats may be correlated with its antioxidant activity and upregulation of NO production.

Topics: Analysis of Variance; Animals; Antioxidants; Blood Pressure; Chi-Square Distribution; Free Radical Scavengers; Heart Rate; L-Lactate Dehydrogenase; Male; Myocardial Ischemia; Myocardial Reperfusion Injury; Nitric Oxide; Rats; Rats, Sprague-Dawley; Resveratrol; Statistics, Nonparametric; Stilbenes; Tachycardia, Ventricular; Ventricular Fibrillation