Kawabata K, Takakura Y, Hashida M
Department of Drug Delivery Research, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Pharm Res. 1995 Jun;12(6):825-30. doi: 10.1023/a:1016248701505.
We examined the stability and disposition characteristics of a naked plasmid DNA pCAT as a model gene after intravenous injection in mice to construct the strategy of in vivo gene delivery systems.
After the injection of pCAT to the mice, stability, tissue distribution, hepatic cellular localization, and effect of some polyanions on the hepatic uptake were studied.
The in vitro study demonstrated that the pCAT was rapidly degraded in mouse whole blood with a half-life of approximately 10 min at a concentration of 100 micrograms/ml. After intravenous injection, pCAT was degraded at a significantly faster rate than that observed in the whole blood, suggesting that pCAT in vivo was also degraded in other compartments. Following intravenous injection of [32P] pCAT, radioactivity was rapidly eliminated from the plasma due to extensive uptake by the liver. Hepatic accumulation occurred preferentially in the non-parenchymal cells. The hepatic uptake of radioactivity derived from [32P] pCAT was inhibited by preceding administration of polyanions such as polyinosinic acid, dextran sulfate, maleylated and succinylated bovine serum albumin but not by polycytidylic acid. These findings indicate that pCAT is taken up by the liver via scavenger receptors on the non-parenchymal cells. Pharmacokinetic analysis revealed that the apparent hepatic uptake clearance was fairly close to the liver plasma flow.
These findings provide useful information for the development of delivery systems for in vivo gene therapy.
我们研究了裸质粒DNA pCAT作为模型基因在小鼠静脉注射后的稳定性和处置特征，以构建体内基因递送系统的策略。
向小鼠注射pCAT后，研究其稳定性、组织分布、肝细胞定位以及一些聚阴离子对肝脏摄取的影响。
体外研究表明，pCAT在小鼠全血中迅速降解，在浓度为100微克/毫升时半衰期约为10分钟。静脉注射后，pCAT的降解速度明显快于在全血中观察到的速度，表明体内的pCAT在其他部位也会降解。静脉注射[32P]pCAT后，由于肝脏的大量摄取，放射性物质迅速从血浆中清除。肝脏积累优先发生在非实质细胞中。预先给予聚阴离子如聚肌苷酸、硫酸葡聚糖、马来酰化和琥珀酰化牛血清白蛋白可抑制源自[32P]pCAT的放射性物质的肝脏摄取，但聚胞苷酸则无此作用。这些发现表明pCAT通过非实质细胞上的清道夫受体被肝脏摄取。药代动力学分析显示，表观肝脏摄取清除率相当接近肝脏血浆流量。
这些发现为体内基因治疗递送系统的开发提供了有用信息。
