Buang Yohanes, Wang Yu-Ming, Cha Jae-Young, Nagao Koji, Yanagita Teruyoshi
Department of Applied Biological Sciences, Saga University, Saga, Japan.
Nutrition. 2005 Jul-Aug;21(7-8):867-73. doi: 10.1016/j.nut.2004.11.019.
We compared the effect of dietary phosphatidylcholine (PC) with that of triacylglycerol (TG), both with the same fatty acid profiles, on fatty infiltration in orotic acid (OA)-induced fatty liver of Sprague-Dawley rats.
Rats were fed an OA-supplemented diets containing TG (TG+OA group) or PC (20% of dietary lipid, PC+OA group) for 10 d. Rats fed the TG diet without OA supplementation served as the basal group.
Administering OA significantly increased the weights and TG accumulation in livers of the TG+OA group compared with the basal group. These changes were attributed to significant increases in the activities of fatty acid synthase, malic enzyme, and glucose-6-phosphate dehydrogenase, which are fatty acid synthetic enzymes, and phosphatidate phosphohydrolase, a rate-limiting enzyme of TG synthesis. However, the PC+OA group did not show TG accumulation and OA-induced increases of these enzyme activities. Further, a significant increase in the activity of carnitine palmitoyl transferase, a rate-limiting enzyme of fatty acid beta-oxidation, was found in the PC+OA group.
Dietary PC appears to alleviate the OA-induced hepatic steatosis and hepatomegaly, mainly through the attenuation of hepatic TG synthesis and enhancement of fatty acid beta-oxidation in Sprague-Dawley rats.
我们比较了具有相同脂肪酸谱的膳食磷脂酰胆碱(PC)和三酰甘油(TG)对斯普拉格-道利大鼠乳清酸(OA)诱导的脂肪肝中脂肪浸润的影响。
给大鼠喂食含TG的OA补充饲料(TG+OA组)或PC(占膳食脂质的20%,PC+OA组),持续10天。喂食不含OA补充剂的TG饲料的大鼠作为基础组。
与基础组相比,给予OA显著增加了TG+OA组大鼠肝脏的重量和TG积累。这些变化归因于脂肪酸合成酶、苹果酸酶和葡萄糖-6-磷酸脱氢酶(均为脂肪酸合成酶)以及TG合成的限速酶磷脂酸磷酸水解酶的活性显著增加。然而,PC+OA组未显示TG积累以及OA诱导的这些酶活性增加。此外,在PC+OA组中发现肉碱棕榈酰转移酶(脂肪酸β氧化的限速酶)的活性显著增加。
在斯普拉格-道利大鼠中,膳食PC似乎主要通过减弱肝脏TG合成和增强脂肪酸β氧化来减轻OA诱导的肝脂肪变性和肝肿大。