大鼠运动性肥大心脏心肌血管内皮生长因子及其基因表达的研究

目的和方法：血管内皮生长因子（ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ，ＶＥＧＦ）是新近确定的一种特异作用于血管内皮细胞的活性肽。最近发现正常心肌细胞可表达ＶＥＧＦ，高血压肥大心脏心肌ＶＥＧＦ及基因表达增强，但对运动性心肌肥大时的变化尚不清楚。本实验采用免疫组化和分子杂交方法，对游泳运动１０周大鼠稳定期肥大心脏心肌ＶＥＧＦ及其基因表达进行研究。结果：ＷｉｓｔａｒＫｙｏｔｏ（ＷＫＹ）大鼠、自发性高血压大鼠（ｓｐｏｎｔａｎｅｏｕｓｌｙｈｙｐｅｒｔｅｎｓｉｖｅｒａｔｓ，ＳＨＲ）和运动大鼠心肌细胞浆内均有特异性ＶＥＧＦ染色颗粒，但运动大鼠心肌细胞胞浆内染色颗粒增加最明显。Ｎｏｒｔｈｅｒｎ分子杂交结果表明三组大鼠心肌均有ＶＥＧＦｍＲＮＡ表达，其中ＳＨＲ表达最强，运动大鼠比ＷＫＹ大鼠增强，但低于ＳＨＲ。结论：目前对这一结果的生理意义还不清楚，推测可能与心肌肥大时细胞间质血管增生有关。

EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR AND ITS GENE IN MYOCARDIUM OF EXERCISE INDUCED HYPERTROPHIED HEART

Aim and Methods: Vascular endothelial growth factor (VEGF), a growth and permeability factor specific for endothelial cell, has been identified in myocardium of the normal adult heart and increased in myocardium of hypertensive hypertrophic heart, but the change of VEGF in myocardium of exercise induced hypertrophic heart is unclear. We therefor studied the expression of VEGF and its gene in myocardium of rats subjected to 10 week swimming program and spontaneously hypertensive rats (SHR) by immunohistochemistry assay and Northern bolt. All the results were analyzed by scanning densitometry. Results: Compared with control Wistar Kyoto (WKY) rats, the left ventricle weight/body weight of swimming rats and SHR were increased by 29% and 61% respectively ( P <0.01). The intracellular VEGF immunoractivity was present in myocardium of WKY rats, SHR and swimming rats, but the immunoractivity of swimming rats was the strongest in the three groups. The results of Northern bolt showed that the expression of VEGF mRNA of swimming rats was increased by 36% than that of WKY and decreased by 19% than that of SHR by scanning densitometry. Conclusion: Although little is known about the role of expression upregulation of VEGF and its gene in myocardium, it seems reasonable to vascular proliferation of swimming induced hypertrophic heart.