组织型纤溶酶原激活剂基因在小鼠体内的表达

t PA cDNA Injected Directly into Mouse Muscle and Expression in Vivo

将组织型纤溶酶原激活剂（ｔ－ＰＡ）基因ｃＤＮＡ经多次亚克隆插入到真核表达载体ｐＳＶＬ的ＳＶ４０启动子和ｐｃＤＮＡ３的ＣＭＶ启动子下游，构建了重组质粒ｐＳＶＬ－ｔＰＡ和ｐｃＤＮＡ３－ｔＰＡ。分别将这２种重组质粒直接注射于小鼠骨骼肌，观察了ｔ－ＰＡ基因在小鼠体内的表达情况。体外凝血试验结果显示，注射重组质粒ＤＮＡ后，第５天凝血时间有所延长，第１５～２０天达到高峰，小鼠体外凝血时间平均延长７ｍｉｎ左右，延长时间与基因注射量呈明显的正相关。

Two expression plasmids, pSVL tPA and pcDNA 3 tPA,containing the tissue type plasminogen activator(t PA)cDNA gene were constructed by inserting into the downstream of the SV 40 Promoter and the CMV Promoter,respectively. The t PA expressed in mouse muscle was observed by direct injection of PSVL tPA and pcDNA 3 tPA into the muscle.The results showed that the prolongation of blood clotting time could be discerned on 5th day after the injection of the recombinant plasmids,and the peak occurred on 15th to 20th day. On an average, the blood coagulation time prolonged for 7 min. There was positive relationship between the dosage of gene injected and the time of blood coagulation prolonged. The results also suggested that the directly injected pSVL tPA and pcDNA 3 tPA could be expressed in vivo and the expressed product would be of biological activity.