diet exercise fatty acids gene expression metabolism phosphates
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摘要

BACKGROUND:Inorganic phosphate (Pi) is used extensively as a preservative and a flavor enhancer in the Western diet. Physical inactivity, a common feature of Western societies, is associated with increased cardiovascular morbidity and mortality. It is unknown whether dietary Pi excess contributes to exercise intolerance and physical inactivity.
METHODS:To determine an association between Pi excess and physical activity in humans, we assessed the relationship between serum Pi and actigraphy-determined physical activity level, as well as left ventricular function by cardiac magnetic resonance imaging, in DHS-2 (Dallas Heart Study phase 2) participants after adjusting for relevant variables. To determine direct effects of dietary Pi on exercise capacity, oxygen uptake, serum nonesterified fatty acid, and glucose were measured during exercise treadmill test in C57/BL6 mice fed either a high-Pi (2%) or normal-Pi (0.6%) diet for 12 weeks. To determine the direct effect of Pi on muscle metabolism and expression of genes involved in fatty acid metabolism, additional studies in differentiated C2C12 myotubes were conducted after subjecting to media containing 1 to 3 mmol/L Pi (pH 7.0) to simulate in vivo phosphate conditions.
RESULTS:In participants of the DHS-2 (n=1603), higher serum Pi was independently associated with reduced time spent in moderate to vigorous physical activity ( P=0.01) and increased sedentary time ( P=0.004). There was no association between serum Pi and left ventricular ejection fraction or volumes. In animal studies, compared with the control diet, consumption of high-Pi diet for 12 weeks did not alter body weight or left ventricular function but reduced maximal oxygen uptake, treadmill duration, spontaneous locomotor activity, fat oxidation, and fatty acid levels and led to downregulation of genes involved in fatty acid synthesis, release, and oxidation, including Fabp4, Hsl, Fasn, and Pparγ, in muscle. Similar results were recapitulated in vitro by incubating C2C12 myotubes with high-Pi media.
CONCLUSIONS:Our data demonstrate a detrimental effect of dietary Pi excess on skeletal muscle fatty acid metabolism and exercise capacity that is independent of obesity and cardiac contractile function. Dietary Pi may represent a novel and modifiable target to reduce physical inactivity associated with the Western diet.

译文

背景: 无机磷酸盐 (Pi) 在西方饮食中被广泛用作防腐剂和增味剂。缺乏运动是西方社会的一个共同特征,与心血管发病率和死亡率的增加有关。目前还不知道饮食中 Pi 过量是否会导致运动不耐受和缺乏运动。
方法: 为了确定人体内 Pi 过量和体力活动之间的联系,我们评估了血清 Pi 和活动描记法确定的体力活动水平之间的关系, 以及心脏磁共振成像的左心室功能,在 DHS-2 (达拉斯心脏研究第二阶段) 中,参与者在调整相关变量后。为了确定饮食 Pi 对运动能力、摄氧量、血清非酯化脂肪酸的直接影响, 在 12 周的高 Pi (2%) 或正常 Pi (0.6%) 饮食的 C57/BL6 小鼠的运动平板试验中测量了葡萄糖。为了确定 Pi 对肌肉代谢和脂肪酸代谢相关基因表达的直接影响, 分化的 C2C12 肌管的额外研究是在接受含有 1 至 3 毫摩尔/升 Pi (pH 7.0) 的介质以模拟体内磷酸盐条件后进行的。
结果: 在 DHS-2 (n = 1603) 的参与者中,较高的血清 Pi 与中度至剧烈体力活动时间的减少独立相关 (P = 0.01) 并且增加了久坐时间 (P = 0.004)。血清 Pi 与左心室射血分数或容积之间无关联。在动物研究中,与对照饮食相比,12 周的高 Pi 饮食并未改变体重或左心室功能,但降低了最大摄氧量、跑步机持续时间, 自发运动活动、脂肪氧化和脂肪酸水平,并导致脂肪酸合成、释放相关基因的下调,和氧化,包括肌肉中的 Fabp4 、 Hsl 、 Fasn 和 ppar γ。通过用高 Pi 培养基孵育 C2C12 肌管,在体外概括了类似的结果。
结论: 我们的数据证明了过量饮食对骨骼肌脂肪酸代谢和运动能力的不利影响,而这与肥胖和心脏收缩功能无关。膳食 Pi 可能代表一种新的和可改变的目标,以减少与西方饮食相关的缺乏运动。

Fatty acid metabolism

内分泌 生化反应 临床研究术语
概述  :  

脂肪酸代谢包括产生能量的分解代谢过程和产生生物学上重要的分子(甘油三酸酯,磷脂,第二信使,局部激素和酮体)的合成代谢过程。 脂肪酸分解代谢 游离脂肪酸一旦从甘油中释放出来,就会进入血液,并通过血浆白蛋白将其运送到全身。长链游离脂肪酸通过特定的转运蛋白进入细胞代谢,如SLC27家族脂肪酸转运蛋白。红细胞不含线粒体,因此无法代谢脂肪酸。尽管含有线粒体,中枢神经系统组织仍无法使用脂肪酸,因为长链脂肪酸无法穿过血脑屏障进入这些细胞的组织液中。一旦

fatty   英 /ˈfæti/   美 /ˈfæti/

释    义   adj. 脂肪的;肥胖的;多脂肪的;脂肪过多的

               n. 胖子

例    句   Moreover, brain tissue contains a great deal of oxidisable material, particularly in the fatty membranes surrounding nerve cells.此外,脑组织内含有许多可氧化的物质,特别是绕在神经细胞周围的脂肪膜。

 

acid   英 /ˈæsɪd/   美 /ˈæsɪd/

释    义   n. 酸;<俚>迷幻药

               adj. 酸的;讽刺的;刻薄的

例    句   Roses will not root in such acid soil.玫瑰在这种酸性土壤中不会生根。

 

metabolism   英 /məˈtæbəlɪzəm/  美 /məˈtæbəlɪzəm/

释    义   n. [生理] 新陈代谢

例    句   All living matter undergoes a process of metabolism.生物都有新陈代谢。

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