Fujiwara M, Nakano T, Tamoto S, Yamada Y, Fukai M, Takada K, Ashida H, Shimada T, Ishihara T, Seki I
First Department of Internal Medicine, Medical College of Osaka, Takatsuki.
J Cardiol. 1991;21(2):493-504.
To assess the protective effects of L-carnitine (LC) infusion on ischemic heart disease, 30 patients who had angina and ischemic ECG changes during exercise were evaluated by bicycle ergometry. They were categorized in LC and non-treatment (NT) groups. There were no significant differences in age and sex between the 2 groups. Before exercise, 15 patients (9 males and 6 females) received 60 mg/kg LC and the results including hemodynamics, coronary circulation, and cardiac metabolism at rest and during exercise were compared with those of the NT group studied in the same protocol (50 watts x to cycle, 15 min). At the end of 30 min LC drip infusion, the arterial carnitine content (LC (a)) reached 1,980 +/- 257.3 microM and then was maintained at 1,212.7 +/- 136.2 microM during exercise. There was no correlation of LC (a) with the coronary arterio-venous difference nor with myocardial uptake of LC. Although there was no significant difference in coronary blood flow (CBF: mliters/100 g/min) between the LC and NT groups at rest (LC: 92.1 +/- 29.0 vs NT: 88.0 +/- 26.5), CBF during exercise increased significantly in the LC group compared with the NT group (LC: 230.4 +/- 113.8 vs NT: 139.1 +/- 52.7; p < 0.05). In the NT group, there was no significant change in coronary arterio-venous oxygen difference ((a-cs) O2: vol %) during exercise, but in the LC group (a-cs) O2 increased significantly from 10.2 +/- 1.3 to 11.5 +/- 1.9 (p < 0.01). Furthermore, although there was no significant difference in myocardial oxygen consumption (MVO2: mliters/100 g/min) at rest between the 2 groups (LC: 9.30 +/- 2.96 vs NT: 9.71 +/- 3.09), it increased significantly in the LC group compared with the NT group during exercise (LC: 25.11 +/- 9.98 vs NT: 15.55 +/- 6.09). MVO2/LVWI (LVWI = left ventricular work index) and MVO2MT (MT = myocardial tension) did not significantly differ at rest between the 2 groups. However, these 2 indices decreased significantly during exercise (p < 0.05) in the NT group, and remained unchanged in the LC group, showing a significant difference between the 2 groups (both p < 0.05). In myocardial energy substrates, the myocardial uptake ((a-cs) x CBF) of free fatty acid (FFA: muEq/100 g/min) increased significantly in the LC group compared with that of the NT group (LC: 10.16 +/- 13.26-->31.88 +/- 27.58* vs NT: 16.02 +/- 27.92-->18.11 +/- 31.00;* = p < 0.05, LC vs NT).
为评估左旋肉碱（LC）输注对缺血性心脏病的保护作用，通过自行车测力计对30例运动期间出现心绞痛和缺血性心电图改变的患者进行了评估。他们被分为LC组和非治疗（NT）组。两组之间在年龄和性别上无显著差异。运动前，15例患者（9例男性和6例女性）接受了60mg/kg的LC，并将静息及运动期间的血流动力学、冠脉循环和心脏代谢结果与按照相同方案（50瓦×骑行，15分钟）研究的NT组进行比较。在30分钟LC静脉滴注结束时，动脉肉碱含量（LC（a））达到1980±257.3微摩尔，然后在运动期间维持在1212.7±136.2微摩尔。LC（a）与冠脉动静脉差值及心肌对LC的摄取均无相关性。尽管LC组和NT组静息时冠脉血流量（CBF：毫升/100克/分钟）无显著差异（LC组：92.1±29.0 vs NT组：88.0±26.5），但与NT组相比，运动期间LC组的CBF显著增加（LC组：230.4±113.8 vs NT组：139.1±52.7；p<0.05）。在NT组中，运动期间冠脉动静脉氧差（（a-cs）O2：容积%）无显著变化，但在LC组中，（a-cs）O2从10.2±1.3显著增加至11.5±1.9（p<0.01）。此外，尽管两组静息时心肌耗氧量（MVO2：毫升/100克/分钟）无显著差异（LC组：9.30±2.96 vs NT组：9.71±3.09），但与NT组相比，运动期间LC组的MVO2显著增加（LC组：25.11±9.98 vs NT组：15.55±6.09）。两组静息时MVO2/LVWI（LVWI=左心室作功指数）和MVO2MT（MT=心肌张力）无显著差异。然而，NT组中这两个指标在运动期间显著降低（p<0.05），而LC组保持不变，两组之间存在显著差异（均为p<0.05）。在心肌能量底物方面，与NT组相比，LC组游离脂肪酸（FFA：微当量/100克/分钟）的心肌摄取（（a-cs）×CBF）显著增加（LC组：10.16±13.26→31.88±27.58* vs NT组：16.02±27.92→18.11±31.00；*=p<0.05，LC组 vs NT组）。
