LIPID SYNTHESIS, INTRACELLULAR TRANSPORT, AND STORAGE
LIPID SYNTHESIS, INTRACELLULAR TRANSPORT, AND STORAGE
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脂质合成、细胞内运输和储存
DOI：
10.1083/jcb.36.1.63
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发表时间：
1968
期刊：
影响因子：
--
通讯作者：
Y. Stein
中科院分区：
文献类型：
--
作者：
O. Stein;Y. Stein
在体外用9，10-油酸-3H灌注15或30秒脉冲标记的大鼠心脏显示出广泛摄取脂肪酸。在用未标记培养基灌注15秒或更长时间的心脏中，90%的放射性在酯化脂质中回收。放射自显影反应最初定位于肌浆网和线粒体的元件上。经过较长时间的后灌注（2-20分钟），有浓度的银颗粒的脂滴。在线粒体和肌浆网分离的心脏postperfused 1分钟或更长时间，大部分的酯化脂质的形式甘油三酯。离体肌浆网甘油三酯与线粒体甘油三酯的比活性在灌注后5分钟内从3.2变为1.3。在低温条件下，发生了相当大的游离脂肪酸摄取。在心脏中回收的放射性主要以游离脂肪酸的形式存在，在肌浆网和线粒体上观察到放射自显影反应，但在脂滴或肌原纤维上未观察到放射自显影反应。结果被解释为表明，细胞内运输的游离脂肪酸，这也发生在酯化被抑制时，通过细胞内通道，即肌浆网进行。脂肪酸酯化成甘油三酯主要发生在肌浆网中，特别是在二分体区域，在其附近脂质以液滴的形式储存。
Rat hearts pulse-labeled by perfusion in vitro with 9,10-oleic acid-3H for 15 or 30 sec were shown to take up the fatty acid extensively. In hearts postperfused with unlabeled medium for 15 sec or more, 90% of the radioactivity was recovered in esterified lipids. The radioautographic reaction was localized initially over elements of the sarcoplasmic reticulum and mitochondria. After longer periods of postperfusion (2–20 min), there was concentration of silver grains over lipid droplets. In mitochondria and sarcoplasmic reticulum isolated from hearts postperfused for 1 min or more, most of the esterified lipid was in the form of triglyceride. The ratio of the specific activity of isolated sarcoplasmic reticulum triglyceride to mitochondrial triglyceride changed from a value of 3.2 to 1.3 during 5 min of postperfusion. Under conditions of hypothermia, considerable uptake of free fatty acid occurred. The radioactivity recovered in the heart was mostly in the form of free fatty acid, and the radioautographic reaction was seen over sarcoplasmic reticulum and mitochondria, but not over lipid droplets or myofibrils. The results are interpreted to show that intracellular transport of free fatty acid, which occurs also when esterification is repressed, proceeds through intracellular channels, i.e. the sarcoplasmic reticulum. Esterification of fatty acid into triglycerides occurs mostly in the sarcoplasmic reticulum, especially in the region of the dyad, in the vicinity of which lipid is stored in the form of droplets.