压力超负荷时大鼠心肌碱性成纤维细胞生长因子表达变化及意义

Alteration of Myocardial bFGF Expression and its Significance in Acute Pressure Overload

目的探讨碱性成纤维细胞生长因子（ｂＦＧＦ）在急性压力超负荷时心肌中的表达及意义。方法采用部分结扎Ｗｉｓｔａｒ大鼠腹主动脉（ＯＧ），并与对照组（ＣＧ）对比检测６个时相点（０．５ｈ，４ｈ，１ｄ，５ｄ，１０ｄ，３０ｄ）的平均动脉压（ＭＡＰ）、左室收缩压（ＬＶＳＰ）、左室重量指数（ＬＶＭＩ）；同时分别用免疫组织化学、原位杂交与图象分析半定量技术相结合的方法检测ｂＦＧＦ蛋白及ｍＲＮＡ表达变化。结果（１）ＭＡＰ、ＬＶＳＰ与ＬＶＭＩ分别从４ｈ和５ｄ（Ｐ＜０．０５）开始逐渐增高直到３０ｄ（Ｐ＜０．０１）；（２）ＯＧ中ｂＦＧＦｍＲＮＡ和蛋白分别从１ｄ及５ｄ开始增加（Ｐ＜０．０５），于５ｄ～１０ｄ达峰值，３０ｄ时恢复正常；（３）ＯＧ中ＬＶＭＩ和ＬＶＳＰ分别与ｂＦＧＦｍＲＮＡ及蛋白在１ｄ、５ｄ、１０ｄ时存在显著正相关关系（ｒ＝０．５４７～０．９５６，Ｐ＜０．０５～０．０１）。结论ｂＦＧＦ可能以自分泌和／或旁分泌方式参与急性压力超负荷致心肌肥大的早期病理过程。

Aim\ To investigate the changes and significance of myocardial bFGF in the course of acute pressure overload of the heart in rat.\ Methods\ Wistar rats underwent partial occlusion of the abdominal aorta(OG) or a sham procedure(CG). At 0.5 h,4 h,1 d,5 d,10 d,30 d after operation, left ventricular mass index(LVMI), mean arterial pressure(MAP), and left ventricular systolic pressure(LVSP) were detected. The expression levels of bFGF mRNA and bFGF protein were studied by in situ hybridization and immunohistochemistry.\ Results\ (1)LVSP and LVMI gradually increased from 4 h and 5 d to 30 d, respectively, after OG(< P <0.01);(2)bFGF mRNA and protein expression levels in OG increased significantly at 1 d and 5 d, reached the peak at 5 d～10 d, and then fell to control levels 30 d after OG;(3)LVMI and LVSP was positively correlated with the level of bFGF mRNA and protein at 1 d～10 d.\ Conclusion\ These data strongly support the hypothesis that bFGF may play role in early stage,but not in late stage, of pressure overload induced myocardiac hypertrophy via autocrine and/or paracrine pathways.