Clouet P, Semporé G, Tsoko M, Gresti J, Demarquoy J, Niot I, Bézard J, Martin-Privat P
Laboratoire de Nutrition Cellulaire et Métabolique, Université de Bourgogne, Faculté des Sciences, Dijon, France.
Biochim Biophys Acta. 1996 Jan 19;1299(2):191-7. doi: 10.1016/0005-2760(95)00206-5.
This study was designed to examine whether short- and long-term treatments by a low level of dietary L-carnitine are capable of altering enzyme activities related to fatty acid oxidation in normal Wistar rats. Under controlled feeding, ten days of treatment changed neither body weights nor liver and gastrocnemius weights, but succeeded in reducing the weight of peri-epididymal adipose tissues. Triacylglycerol contents were lowered in liver and ketone body concentrations were found slightly more elevated in blood. In the liver, mitochondrial carnitine palmitoyltransferase I (CPT I) exhibited a slightly higher specific activity and a lower sensitivity to malonyl-CoA inhibition, while peroxisomal fatty acid oxidizing system (PFAOS) was found to be less active. Carnitine supplied for one month reduced the mass of the periepididymal fat tissue, but not those of the other studied organs, and produced a slight but non-significant gain in body weight after ten days of treatment. In the liver, CPTI characteristics were comparable in control and treated groups, while PFAOS activity was less in rats receiving carnitine. Data show that L-carnitine at a low level in the diet exerted two paradoxical effects before and after ten days of treatment. Results are discussed in regard to fatty acid oxidation in mitochondria and peroxisomes, and to the possible altered acyl-CoA/acylcarnitine ratio with increased concentrations of L-carnitine in the liver.
本研究旨在探讨低水平膳食L-肉碱的短期和长期处理是否能够改变正常Wistar大鼠中与脂肪酸氧化相关的酶活性。在控制喂养条件下，十天的处理既未改变体重，也未改变肝脏和腓肠肌重量，但成功降低了附睾周围脂肪组织的重量。肝脏中三酰甘油含量降低，血液中酮体浓度略有升高。在肝脏中，线粒体肉碱棕榈酰转移酶I（CPT I）表现出略高的比活性和对丙二酰辅酶A抑制的较低敏感性，而过氧化物酶体脂肪酸氧化系统（PFAOS）的活性较低。供应一个月的肉碱减少了附睾周围脂肪组织的质量，但未改变其他研究器官的质量，并且在处理十天后体重略有增加但不显著。在肝脏中，对照组和处理组的CPTI特征相当，而接受肉碱的大鼠中PFAOS活性较低。数据表明，膳食中低水平的L-肉碱在处理十天前后产生了两种矛盾的效应。就线粒体和过氧化物酶体中的脂肪酸氧化以及肝脏中L-肉碱浓度增加可能改变的酰基辅酶A/酰基肉碱比值进行了讨论。
