بررسي اثرال - كارنيتين بر روي اندازه انفاركت ناشي از اپكمي - پرفيوژن مجدد در قلب ايزوله موش صحرايي

Study the effect of L-Carnitine on Infarct Size in the Ischemic-Reperfused Isolated Rat Hearts

Carnitine is a vital biologic substance for transporting fatty acids into myocytes and facilitates fatty acids p-oxidation for energy production. There are some conflicting findings about its cardioprotective effects such as decreasing the infarct size during ischemia / reperfusion. In this study,the effects of L-Carnitine on infarct size in the ischemic isolated rat hearts were investigated. Male Sprague-Dawley rats (270-330g) were divided into 5 groups randomly and they were anesthetized by sodium pentobarbital (50-60 mg/kg-ip).Heart was removed and quickly mounted on a Langendorff apparatus and perfused by a modified Krebs -Henseleit solution under constant pressure at 37 C °. In control group (n=6), the hearts were perfused only by normal Krebs -Henseleit solution at stabilization, 30 min regional ischemia and 120 min reperfusion, while in the test groups (1-4 groups , n=6 in each group), during ischemia / reperfusion , the hearts were perfused with 0.5,2.5,3.75 and 5mM of L-Carnitine - enriched Krebs -Henseleit solution , respectively. At the end of reperfusion, 1% Evans Blue solution was infused to stain the nonischemic area. Then the heart was cut into slices and incubated by 1% Triphenyltetrazolium chloride (TTZ) solution and fixed by formalin. The area of infracted tissue and area at risk were determined by computerized planimetry. In control group, the infarct size was 46.29 ±3.46%, while in the test groups, the addition of L-Carnitine (0.5, 2.5, 3.75 and 5mM) into the Krebs solution during ischemia and reperfusion, reduced infarct size to 27 ± 2.85, 25.53 ± 5.40, 19.53 ± 4.88 andl5.68 ± 2.78 %, respectively (p<0.001).The effect was dose-dependent at the doses of 0.5 -5mM.There was no significant difference between and within test groups using ANOVA one-way test. Considering these results, we conclude that L-carnitine has a protective effect against cardiac ischemic reperfusion injuries and reduces the infarct size.