- 著者
- Yoshikazu SUZUKI Tadashi KAMIKAWA Noboru YAMAZAKI
- 出版者
- Japanese Heart Journal Association
- 雑誌
- Japanese Heart Journal (ISSN:00214868)
- 巻号頁・発行日
- vol.22, no.2, pp.219-225, 1981 (Released:2008-12-09)
- 参考文献数
- 23
- 被引用文献数
- 7 12
The effect of L-carnitine on cardiac hemodynamics was evaluated in normal closed chest dogs. Extracorporeal circulation was produced to measure coronary blood flow in closed chest dogs. Coronay venous blood was introduced to the extracorporeal circuit through a polyethylene catheter wedged into the coronay sinus under fluoroscopic control and was returned to the animal through the left jugular vein. L-carnitine was infused intravenously at a constant rate of 80mg/Kg/min for 8min. Hemodynamic responses appeared within 1 to 3min of carnitine infusion and peak effects were observed nearly after 5min. Peak effects on cardiac hemodynamics after 5 to 8min of carnitine infusion were as follows. Heart rate decreased by 17% from control (p<0.05). Aortic and left ventricular pressure increased by 20% (p<0.05 and p<0.01 respectively) and peak positive left ventricular dp/dt increased by 35% (p<0.01), the mean rate pressure product as the index of myocardial oxygen consumption remained unchanged. Coronary blood flow increased by 60% (p<0.001) and coronary vascular resistance decreased by 25% (p<0.01). As the infusion of carnitine was discontinued, the effects promptly disappeared. These data suggest that L-carnitine has direct vasodilating and positive inotropic effects on cardiovascular system.
- 著者
- YOSHIKAZU SUZUKI TADASHI KAMIKAWA NOBORU YAMAZAKI
- 出版者
- 日本循環器学会
- 雑誌
- JAPANESE CIRCULATION JOURNAL (ISSN:00471828)
- 巻号頁・発行日
- vol.45, no.5, pp.552-559, 1981-05-20 (Released:2008-04-14)
- 参考文献数
- 38
- 被引用文献数
- 12 18
The effects of L-carnitine on ventricular arrhythmias were evaluated in dogs with acute myocardial ischemia and a supplement of excess free fatty acids (FFA). Acute myocardial ischemia was induced by ligation of left anterior descending coronary artery. After 80 minutes of coronary occlusion, high plasma FFA was induced by intravenous injection of heparin 200 u/kg and Intralipid(R) 5 ml/kg as a bolus. After additional 60 minutes, beating hearts were removed from animals and tissue levels of free carnitine, short and long chain acyl carnitine, FFA and adenosine triphosphate (ATP) were determined. L-carnitine 100 mg/kg was administered intravenously 5 minutes before coronary artery ligation. Electrocardiograms were recorded continuously by a Holter electrocardiographic recorder during the experiment and ventricular arrhythmias were quantified by an arbitrary scoring system. In ischemic and excess FFA supplemented myocardium, free carnitine and ATP decreased, whereas long chain acyl carnitine and FFA increased. And these metabolic changes tended to be reduced by L-carnitine. Pretreatment of L-carnitine also reduced the grade of ventricular arrhythmias induced both by acute myocardial ischemia and by supplement of excess FFA. These results suggest that the administration of L-carnitine may be beneficial to prevent serious arrhythmias in ischemic heart disease, presumably by restoring the impaired FFA oxidation.