McDougall I R, Dunnick J K, McNamee M G, Kriss J P
Proc Natl Acad Sci U S A. 1974 Sep;71(9):3487-91. doi: 10.1073/pnas.71.9.3487.
Single compartmental spherules of various lipid constituents (vesicles), enclosing (99m)TcO(4) (-) as a radioactive marker, were injected intravenously into C(3)H mice, and the distribution of radioactivity was studied. About 25% of the administered radioactivity was present in the liver 5 min and 30 min after the injection of vesicles composed of phosphatidylcholine and gangliosides, which were sonicated for 5 min (standard preparation). About 10-20% of the radioactivity remained in the circulation. By use of a nonradioactive spin label (tempocholine) enclosed within vesicles, intact vesicles were demonstrated in the circulation for 46 min after intravenous injection. The distribution of radioactivity from (99m)TcO(4) (-) inside vesicles is very different from that of free (99m)TcO(4) (-) or of (99m)Tc sulfur colloid. Increase in the length of sonication or incorporation of cholesterol into the wall of the vesicles enhanced hepatic levels and reduced blood levels of radioactivity. These same manipulations also slowed the rate of transfer of (99m)TcO(4) (-) out of vesicles in dialysis experiments in vitro. Addition of phosphatidic acid, phosphatidylethanolamine, or phosphatidylserine to the standard constituents did not greatly alter the distribution of radioactivity in vivo but did increase the number and type of active coupling sites on the outside of the vesicle. The results indicate that vesicles might be valuable as carriers of diagnostic or therapeutic agents.
将包裹着作为放射性标记物的（99m）TcO(4) (-) 的各种脂质成分的单室小球（囊泡）静脉注射到C(3)H小鼠体内，并研究放射性分布。注射经5分钟超声处理的由磷脂酰胆碱和神经节苷脂组成的囊泡（标准制剂）后5分钟和30分钟，约25%的给药放射性存在于肝脏中。约10%-20%的放射性保留在循环系统中。通过使用包裹在囊泡内的非放射性自旋标记物（tempocholine），静脉注射后在循环系统中证实完整的囊泡存在46分钟。囊泡内（99m）TcO(4) (-) 的放射性分布与游离（99m）TcO(4) (-) 或（99m）Tc硫胶体的分布非常不同。超声处理时间的延长或胆固醇掺入囊泡壁会提高肝脏中的放射性水平并降低血液中的放射性水平。在体外透析实验中，这些相同的操作也减缓了（99m）TcO(4) (-) 从囊泡中转移的速率。向标准成分中添加磷脂酸、磷脂酰乙醇胺或磷脂酰丝氨酸不会显著改变体内放射性分布，但会增加囊泡外部活性偶联位点的数量和类型。结果表明，囊泡作为诊断或治疗剂的载体可能具有价值。
