Szklarczyk A, Kaczmarek L
Nencki Institute of Experimental Biology, Warsaw, Poland.
J Neurosci Methods. 1995 Aug;60(1-2):181-7. doi: 10.1016/0165-0270(95)00010-r.
As a prerequisite for blocking specific gene expression in the brain, the pharmacokinetics of two radiolabelled analogs of antisense oligodeoxyribonucleotides (unmodified O-ODN and nuclease resistant phosphorothioate S-ODN) were examined by infusion into the baso-lateral nucleus of amygdala. Both ODN analogs were found to penetrate at restricted distances into the brain tissue. Rapidly after injection, O-ODN was almost completely degraded, while S-ODN remained intact up to 24 h following administration as examined by gel electrophoresis of nucleic acids recovered from the injection site. The tissue clearance of the radioactivity delivered in a form of O-ODN and S-ODN was also different, the former characterized by much better tissue retention. Microscopic studies suggested that S-ODN can apparently penetrate across the cell membrane and accumulate both in the cytoplasm in the cell nucleus. In situ hybridisation histochemistry experiments (antisense probe to injected ODN) revealed that injected S-ODN was present in a form available for annealing with the complementary strand. Our results provide a basic description of the distribution, retention, and stability of antisense oligonucleotides injected into brain tissue.
作为在大脑中阻断特定基因表达的前提条件，通过向杏仁核基底外侧核注入放射性标记的反义寡脱氧核苷酸的两种类似物（未修饰的O-ODN和耐核酸酶的硫代磷酸酯S-ODN）来研究其药代动力学。发现这两种ODN类似物在脑组织中的穿透距离有限。注射后，O-ODN迅速几乎完全降解，而通过对从注射部位回收的核酸进行凝胶电泳检测发现，S-ODN在给药后长达24小时仍保持完整。以O-ODN和S-ODN形式递送的放射性物质的组织清除率也不同，前者的特点是组织保留更好。显微镜研究表明，S-ODN显然可以穿透细胞膜并在细胞质和细胞核中积累。原位杂交组织化学实验（针对注射的ODN的反义探针）显示，注射的S-ODN以可与互补链退火的形式存在。我们的结果提供了对注入脑组织的反义寡核苷酸的分布、保留和稳定性的基本描述。
