Effects of L-carnitine in acute myocardial ischaemia.
Data in the literature suggest that exogenous L-carnitine improves the metabolic function of ischaemic heart cells: it enhances the transport of long-chain fatty acids into the mitochondria, stimulates the slowed beta-oxidation, and moderates the accumulation of amphiphilic acyl esters. A study has therefore been made of the cardiac effects of L-carnitine in dog experiments (n = 8). The left anterior descending coronary artery (LAD) was isolated in anaesthetized, thoracotomized animals in situ. After a control occlusion and equilibration period, the LAD was again ligated at the time of L-carnitine infusion (100 mg/kg iv. during 10 min). The agent diminished the maximal conduction delay and the degree of epicardial ST-segment elevation in the ischaemic myocardial region, and the free fatty acid concentration of the arterial blood, but it did not influence the frequency of ventricular extrasystoles. The anti-ischaemic effect of L-carnitine was manifest only during the infusion, and its discontinuation was immediately followed by an enhanced ST-segment elevation. In the dose applied, the substance did not affect the heart rate, systemic mean arterial pressure, left ventricular end-diastolic pressure (LVEDP), or left ventricular contractility (LV dP/dtmax). In the canine myocardial infarction model employed it was observed that the duration of the anti-ischaemic effect of L-carnitine (100 mg/kg iv.) is very short, and it has no significant antiarrhythmic action.
D000208:Acute Disease; D000818:Animals; D001158:Arteries; D001794:Blood Pressure / Q000187:drug effects; D002331:Carnitine / Q000627:therapeutic use*; D003327:Coronary Disease / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D004285:Dogs; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects
D005230:Fatty Acids, Nonesterified; D002331:Carnitine