THE DOSE-DEPENDENT EFFECTS OF L-CARNITINE IN MYOCARDIAL PROTECTION INNORMOTHERMIC ISCHEMIA

L-Carnitine has been shown to improve the post-ischemic recovery of my ocardial function and metabolic measurements that are reduced in the c ourse of ischemia and reperfusion of the heart. In this study we used 40 male guinea-pigs in order to determine if the effect of L-carnitine which is used in the protection of the post-ischemic reperfused heart , is dose-dependent or not, All harvested hearts were perfused for 30 min on modified Langendorf apparatus with oxygenized Krebs-Henseleit s olution. After this period, in (n = 10), 5 mmol and 10 mmol (group B. n = 10) of L-carnitine were added into a Krebs-Henseleit solution. Aft er 20 min, perfusion was complete and the hearts were then exposed to normothermic ischemia for 20 minutes. Following the ischemia, hearts w ere reperfused with the same solutions for 30 min. In group C (n = 10) , 10 mmol of L-carnitine was added into the solution at the postischem ic reperfusion step. In the control group, the same procedures were pe rformed without using L-carnitine, Matching was done according to the contractile force of the heart rate and the levels of malondialdehyde and adenosine deaminase, When 10 mmol L-carnitine was added into the p erfusion solutions at the pre-ischemic period, the best results were o btained and myocardial damage was much less than the control group, Th e protective effects of L-carnitine in normothermic ischemia is dose-d ependent and it must be given at the pre-ischemic period. (C) 1998 The International Society for Cardiovascular Surgery. Published by Elsevi er Science Ltd. All rights reserved.