Maeda H, Fujiwara M, Fujita K, Fukuda N
Faculty of Health and Living Sciences, Naruto University of Education, Japan.
J Nutr Sci Vitaminol (Tokyo). 1996 Apr;42(2):111-20. doi: 10.3177/jnsv.42.111.
The effect of emeriamine, a potent inhibitor of the entry of fatty acids into mitochondria on lipid metabolism, was examined. Emeriamine (10 mg/kg body weight) was orally administered to rats under the two different physiological conditions of a 2-day fast or refeeding with a high-carbohydrate diet after a 2-day fast. When rats were refed with a high-carbohydrate diet, serum and hepatic ketone bodies and the levels of free fatty acids decreased, and triglycerides significantly increased compared with fasting rats. However, no significant effect of emeriamine on serum and hepatic lipids was observed between two refeeding groups with or without emeriamine. Conversely, when emeriamine was administered to fasting rats, the levels of serum and hepatic triglycerides increased about 11- and 5-fold, respectively. However, the increased level of hepatic triglycerides was not accompanied by the activities of fatty acid synthetase and NADPH-generating enzymes. The analysis of serum lipoprotein revealed that very low-density lipoprotein consisted of triglyceride-rich particles and there were less apolipoproteins in the fasting rat given emeriamine. We also determined the 120-kDA protein content, which was probably dependent on lipogenesis. The level of 120-kDa protein was greatly increased with or without the administration of emeriamine after refeeding with a high-carbohydrate diet, but the concentration of 120-kDa protein was slight in the fasting rat with emeriamine. These results suggest that specific inhibition of fatty acid oxidation by emeriamine diverted the exogenous fatty acid to the esterification pathway, and induced fatty liver and hypertriglyceridemia under fasting conditions.
研究了强力霉素(emeriamine)这种脂肪酸进入线粒体的有效抑制剂对脂质代谢的影响。在禁食2天或禁食2天后重新喂食高碳水化合物饮食这两种不同生理条件下,给大鼠口服强力霉素(10毫克/千克体重)。当大鼠重新喂食高碳水化合物饮食时,与禁食大鼠相比,血清和肝脏中的酮体以及游离脂肪酸水平降低,甘油三酯显著增加。然而,在有或没有强力霉素的两个重新喂食组之间,未观察到强力霉素对血清和肝脏脂质有显著影响。相反,当给禁食大鼠服用强力霉素时,血清和肝脏甘油三酯水平分别增加了约11倍和5倍。然而,肝脏甘油三酯水平的升高并未伴随着脂肪酸合成酶和NADPH生成酶的活性增加。血清脂蛋白分析显示,极低密度脂蛋白由富含甘油三酯的颗粒组成,在服用强力霉素的禁食大鼠中载脂蛋白较少。我们还测定了可能依赖于脂肪生成的120-kDA蛋白含量。在重新喂食高碳水化合物饮食后,无论是否给予强力霉素,120-kDa蛋白水平都大幅增加,但在服用强力霉素的禁食大鼠中120-kDa蛋白浓度较低。这些结果表明,强力霉素对脂肪酸氧化的特异性抑制将外源性脂肪酸转向酯化途径,并在禁食条件下诱发脂肪肝和高甘油三酯血症。