老年大鼠心肌缺血后VEGF及其亚型的表达

The expression of vascular endothelial growth factor (VEGF) and its isoforms after acute myocardial infarction in aged rats

目的探讨老年急性心肌缺血后VEGF各亚型表达特点,为老年心血管疾病的促血管生成治疗奠定基础。方法复制老龄大鼠心肌梗死模型,采用RT-PCR技术同管扩增VEGF和内参基因,比较VEGF各亚型与内参基因的比值,VEGF120、164、188的和为总VEGF。结果老年大鼠心脏总VEGFmRNA在缺血各阶段明显少于年青大鼠(P<0.01),而且达到峰值的时间推迟,老年大鼠第6小时总VEGFmRNA与GAPDH的比值(2.86±0.19)明显低于年青大鼠第3小时的比值(6.09±0.30)(P<0.001)。缺血后各时间点年青和老年大鼠的VEGF164所占比例最高,VEGF120最低。老年大鼠VEGF188的表达比例增加。结论老年大鼠心肌缺血后VEGF表达减少,而且没有血管生成活性的VEGF188所占比例增加,可能导致老年缺血心肌血管生成能力下降。

Objective To investigate the features of vascular endothelial growth factor （VEGF） and its isoforms after acute myocardial infarction （AMI） in aged rats to found the base for angiogenesis treatment of cardiovascular disease in aged. Methods The AMI rat model was replicated to amplify VEGF and inner control gene with RT-PCR and to compare the ratio of VEGF isoforms （ including VEGF120, 164 and 188） and inner control genes. Results The amount of total VEGF mRNA was fewer in aged rats than that in young rats at all time point （P 〈 0. 01 ）, reaching the peak value later in aged rats. The ratio of total VEGF mRNA and GAPDH （2. 86±0. 19） at the 6th hour in aged rats was lower than that in young rats （6.09±0. 30） at the 3rd hour （P 〈 0.001 ）. All the aged and young rats had the highest level of VEGF164 and the lowest level of VEGF120 at all time points. The ratio of VEGF188 isoform to total VEGF was higher in aged rats. Conclusions The decreased expression of VEGF and increased ratio of VEGF188 which has no angiogenesis function might induce the impaired angiogenesis in aged rat myocardium.