缺血-再灌流致骨骼肌内源性碱性成纤维细胞生长因子mRNA表达

Ischemia and reperfusion reduce the mRNA expression of endogenous basic fibroblast growth factor (bFGF) in rat skeletal muscles

目的研究碱性成纤维细胞生长因子（ｂＦＧＦ）ｍＲＮＡ在正常、缺血以及缺血和再灌流骨骼肌中的表达。方法利用大鼠后肢缺血再灌流损伤模型，采用原位杂交方法与定量ＰＣＲ技术，观察ｂＦＧＦｍＲＮＡ在正常与创伤骨骼肌的定位特征与表达量的改变。结果在未缺血骨骼肌，ｂＦＧＦｍＲＮＡ染色为棕黑色，呈点状或点片状弥散分布于胞浆中，其阳性表达率为８２％。在缺血以及缺血与再灌流损伤的骨骼肌，ｂＦＧＦｍＲＮＡ的分布方式没有改变，但其染色强度与密度却明显减弱，肌纤维ｂＦＧＦｍＲＮＡ阳性染色率分别为５２％和２２％。结论创伤导致骨骼肌内源性ｂＦＧＦｍＲＮＡ表达量减少，进而导致ｂＦＧＦ产生减少，是缺血与再灌流条件下骨骼肌中内源性ｂＦＧＦ含量减少的重要原因之一。

Objective To explore the expression of bFGF gene in normal and wounded rat skeletal muscles. Methods In situ hybridization and quantitative PCR methods were used to evaluate the location of basic fibroblast growth factor (bFGF) mRNA and the amount of bFGF mRNA expression in normal, ischemic or ischemic and reperfused rat skeletal muscles. Results According to the intensity of the stain in situ hybridization, four main classes of fibers could be identified: strong, moderate, weak and negative stained fibers. bFGF mRNA was found in the cytoplasm in both normal and wounded muscles; however, the signal intensity was much stronger in normal muscles. In the normal muscles, bFGF mRNA was distributed irregularly and sparsely, and 82% of fibers had positive bFGF mRNA staining, and only 52% and 22% of fibers in ischemic or ischemic and reperfused muscles were positive for bFGF mRNA staining in situ hybridization. The results in quantitative PCR study supported the concept of the reduced bFGF mRNA expression in the wounded muscles. Conclusions The loss of stored bFGF in wounded skeletal muscles as we showed previously is also caused by its increased damage and reduced secretion.