Takakura Y, Mahato R I, Yoshida M, Kanamaru T, Hashida M
Department of Drug Delivery Research, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Antisense Nucleic Acid Drug Dev. 1996 Fall;6(3):177-83. doi: 10.1089/oli.1.1996.6.177.
The objective of this study was to examine the hepatic disposition characteristics of 20-mer model phosphodiester oligonucleotide (PO) and its partially phosphorothioated (PS3) and fully phosphorothioated (PS) derivatives in the single-pass isolated rat liver perfusion system. [32P]-labeled oligonucleotides were momentarily introduced into this system through the portal vein as a bolus input mode, and the venous outflow patterns were evaluated using statistical moment analysis. The apparent volumes of distribution of these oligonucleotides were greater than those of reference substances for vascular space (erythrocytes) and extracellular space (human serum albumin), indicating a significant interaction between oligonucleotides and the liver. Significant hepatic uptake of oligonucleotides was also observed. About 20%, 36%, and 52% of the injected dose (3 micrograms/rat) was taken up by the liver during a single passage after bolus injection of PO, PS3, and PS, respectively. In the case of PS injection, slow efflux from the liver was observed in the latter phase of perfusion. This suggests that the hepatic uptake process of these oligonucleotides greatly depended on their types. The results of collagenase perfusion experiments suggest that PS3 oligonucleotides were taken up by both liver parenchymal and nonparenchymal cells. The amount of total recovery in the liver decreased substantially by coadministration of polyinosinic acid, dextran sulfate, polycytidic acid and 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid. This suggests that PS3 was taken up by the liver as an anionic molecule in a nonspecific manner.
本研究的目的是在单通道离体大鼠肝脏灌注系统中，研究20聚体模型磷酸二酯寡核苷酸（PO）及其部分硫代磷酸化（PS3）和完全硫代磷酸化（PS）衍生物的肝脏处置特征。[32P]标记的寡核苷酸通过门静脉以团注输入模式瞬间引入该系统，并使用统计矩分析评估静脉流出模式。这些寡核苷酸的表观分布容积大于血管内空间（红细胞）和细胞外空间（人血清白蛋白）的参考物质，表明寡核苷酸与肝脏之间存在显著相互作用。还观察到寡核苷酸有显著的肝脏摄取。分别静脉注射PO、PS3和PS后，单次通过肝脏时，肝脏摄取的注射剂量（3微克/大鼠）分别约为20%、36%和52%。在注射PS的情况下，在灌注后期观察到肝脏有缓慢的流出。这表明这些寡核苷酸的肝脏摄取过程很大程度上取决于它们的类型。胶原酶灌注实验结果表明，PS3寡核苷酸被肝实质细胞和非实质细胞摄取。同时给予聚肌苷酸、硫酸葡聚糖、聚胞苷酸和4-乙酰氨基-4'-异硫氰基芪-2,2'-二磺酸后，肝脏中的总回收率大幅下降。这表明PS3以阴离子分子的形式被肝脏非特异性摄取。
