内毒素致兔线粒体DNA基因突变的SSCP检测

将20只健康实验用白兔随机分为4组（5只／组）：正常对照组（A组）、阳离子A处理组（B组）、内毒素处理组（C组）、阳离子A＋内毒素处理组（D组），运用改进的碱变性法提取肝细胞的线粒体DNA（mitochondrial DNA，mtDNA），设计4对引物扩增mtDNA的tRNA^Leu（UUR）、tRNA^Lys、ATPase8、ATPase6基因，同时运用分光光度计法对扩增产物进行质量鉴定，并运用聚合酶链式反应-单链构象多态性分析技术对PCR产物进行突变分析。结果发现：c组tRNA^Leu（UUR）基因在凝胶中的带型出现泳动异常，表明该基因发生了碱基突变，序列测定表明该突变为2716位的A—G点突变，同时其他各组的tRNA^Leu（UUR）基因无突变发生。该结果提示内毒素可以导致mtDNA的tRNA^Leu（UUR）基因发生突变，而阳离子A对这一突变具有保护效应。

SSCP detection of ET-induced mtDNA mutation in rabbits

To study the mutational effect of endotoxin (ET)-induced mitochondrial DNA(mtDNA),20 white rabbits were divided randomly into 4 groups of 5 rabbits each: normal control group (group A), CA treated group (group B), ET treated group (group C), and CA+ET treated group (group D). The liver mtDNA was extracted for detecting the mutations of tRNALeu(UUR), tRNALys, ATPase8, ATPase6 genes by polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) technique. The results revealed that a mutation happened in the tRNALeu(UUR) gene of group C, the sequencing results showed this mutation was an A2716G transition point mutation, no mutations of this gene were detected in group A, B and D; it can be concluded from these results that free radicals (FRs) induced by ET could cause the mutation of mtDNA tRNALeu(UUR) gene, and CA has antagonistic and protective effect on this mutation of tRNALeu(UUR) gene caused by ET.