肌内注射质粒DNA对蟾蜍骨骼肌收缩能力的影响

Effects of injecting plasmid DNA into toad skeletal muscle on its contractility

目的:应用蟾蜍坐骨神经腓肠肌标本,观察肌内注射质粒DNA后不同时间对肌肉收缩功能的影响。方法:重组DNA制备pcDNA3/ANP。分别将任氏液、pcDNA3/ANP及载体pcDNA3注入对照组、pcDNA3/ANP及组pcDNA3组蟾蜍腓肠肌,间隔1 h,2 h,4 h,8 h,24 h及48 h后,处死动物,制备坐骨神经腓肠肌样本,利用BL-410计算机生物机能实验系统测肌肉的单收缩力和强直收缩力。结果:质粒pcDNA3及pcDNA3/ANP肌内注射后,肌肉的单收缩力及强直收缩力与对照组相比均呈现先降低后升高的趋势(P均<0.01);而pcDNA3和pcDNA3/ANP 2者对肌肉的作用差异无统计学意义(P>0.05)。结论:质粒DNA注射入骨骼肌细胞之后除目的基因的表达之外,还可以影响肌肉的收缩功能。

Aim: To investigate the effects of injecting plasmid DNA into toad skeletal muscle on its contractility. Methods :pcDNA3/ANP had been prepared by the method of DNA recombination. Ringer's solution,plasmid DNA pcDNA3 and pcDNA3/ANP were respectively injected into the gastrocnemius of toads of control group,pcDNA3 group,and pcDNA3/ ANP group. Then the twitch force and the tetanic force of the muscles were measured by a computer experimental apparatus at difference times. Results: After plasmid DNA pcDNA3 and pcDNA3/ANP were injected into toad skeletal muscles, the twitch force and tetanic force of gastrocnemius were firstly decreased and later increased ( P < 0. 01) compared with the control group,but there was no significant difference between the effects of pcDNA3 and pcDNA3/ANP on muscles (P > 0.05). Conclusion: The injection of plasmid DNA into skeletal muscle cells could influence the contractility of skeletal muscle besides its expressing interested gene.