[Effects of lipoic acid on reperfusion induced arrhythmias and myocardiac action potential alterations induced by free radical generating system].
By means of Langendorff method the isolated rat heart was perfused with Krebs Henseleit solution. Following ligation of the left descending coronary artery for 10 min the heart was reperfused for 3 min. The incidence of ventricular fibrillation in the reperfusion period was 100%, and the normal sinus rhythm time was shortened to 29 s within 3 min of reperfusion. Administration of lipoic acid (6.8 X 10(-6)-1.7 X 10(-4) mol/L) to the perfusate significantly reduced the incidence of ventricular fibrillation to 33-50% and prolonged the normal sinus rhythm time to 97-107 s. APA, RP, and Vmax recorded from the guinea pig papillary muscle were depressed due to the deleterious effect of xanthine oxidase and hypoxanthine free radical generating system. Under the treatment of lipoic acid (3.5 X 10(-5) mol/L), the depression of APA, RP, and Vmax were significantly relieved. This confirms that lipoic acid treatment, owing to its free radical scavenger effect, is able to protect myocardium from free radical induced electrophysiological abnormalities, and consequently decrease the incidence of malignant arrhythmias.
Gao
T L
TL
Department of Biology, Beijing University.
Huang
Y Z
YZ
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology* / Q000517:prevention & control; D005260:Female; D016166:Free Radical Scavengers; D005609:Free Radicals; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology*; D010100:Oxygen / Q000378:metabolism; D010210:Papillary Muscles / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D008063:Thioctic Acid / Q000494:pharmacology*
D016166:Free Radical Scavengers; D005609:Free Radicals; D008063:Thioctic Acid; D010100:Oxygen