Takada G, Onodera H, Tada K
Tohoku J Exp Med. 1981 Jun;134(2):103-14. doi: 10.1620/tjem.134.103.
Either unentrapped (free) or liposome-entrapped 131I-labeled beta-galactosidase was injected into rats from tail veins. Tissue distribution and intracellular localization of the radioactivity of both sources were compared. The half-life of liposome-entrapped enzyme in the circulation was much longer than that of the free enzyme. The radioactivity removed from the circulation was recovered primarily in the liver, and to a lesser extent in almost all tissues studied. A small but significant uptake of liposome-entrapped enzyme by the brain was also observed. Uptake of liposome-entrapped enzyme was greater thant that of free enzyme in the spleen, heart, lungs and brain, excepting the liver and kidneys. Subcellular fractionation showed distribution of the radioactivity of liposome-entrapped enzyme favoring the mitochondrial-lysosomal fraction from these tissues except the heart. There was a difference in the pattern of intracellular distribution of the radioactivity in the brain of rats between the administration of free enzyme and that of liposome-entrapped enzyme. These findings suggest that when liposomes containing beta-galactosidase were injected into rats from the tail veins, they would penetrate the blood-brain barrier and would reach the lysosomes in the central nervous system tissue more effectively than the free enzyme itself. Beta-galactosidase; liposome; enzyme replacement therapy; rat tissues, 131I.
将未包裹（游离）或脂质体包裹的¹³¹I标记的β-半乳糖苷酶经大鼠尾静脉注射。比较了两种来源放射性的组织分布和细胞内定位。脂质体包裹的酶在循环中的半衰期比游离酶长得多。从循环中清除的放射性主要在肝脏中回收，在几乎所有研究的组织中回收程度较低。还观察到脂质体包裹的酶在脑中少量但显著的摄取。除肝脏和肾脏外，脂质体包裹的酶在脾脏、心脏、肺和脑中的摄取量大于游离酶。亚细胞分级分离显示，脂质体包裹的酶的放射性分布有利于这些组织（心脏除外）的线粒体-溶酶体部分。游离酶给药和脂质体包裹的酶给药后，大鼠脑中放射性的细胞内分布模式存在差异。这些发现表明，当将含有β-半乳糖苷酶的脂质体经大鼠尾静脉注射时，它们会穿透血脑屏障，并且比游离酶本身更有效地到达中枢神经系统组织中的溶酶体。β-半乳糖苷酶；脂质体；酶替代疗法；大鼠组织，¹³¹I
