碱性成纤维细胞生长因子在低氧大鼠肺动脉的表达及其对肺动脉张力的影响

Expression of bFGF mRNA in pulmonary artery of rat with chronic hypoxia and its effect on tension of rat pulmonary artery in vitro

目的 :观察碱性成纤维细胞生长因子 (bFGF)在低氧性肺动脉高压发病中的可能作用。方法 :应用逆转录多聚酶联反应 (RT -PCR)技术观察低氧大鼠肺动脉bFGF的表达水平 ,并观察bFGF对离体大鼠肺动脉环收缩功能的影响。结果 :①低氧时 ,肺动脉bFGFmRNA表达明显增加 ,bFGF与 β -actin的RT -PCR反应产物的放射强度 (counts·min-1)之比由对照的 0 5 0 74上升到 0 9182 (低氧 1周 )和 0 7812 (低氧 2周 ) (P均 <0 0 5 )。②bFGF能收缩离体大鼠肺血管环 ,收缩强度与剂量相关 (r=0 6 95 ,P <0 0 5 ) ,其EC50 为 2 6 2× 10 -7mol/L。结论 :提示bFGF可能参与低氧性肺动脉高压的发病过程。

AIM: To explore the role of basic-fibroblast growth factor (bFGF) in the development of pulmonary hypertension induced by hypoxia. METHODS: 1) The pulmonary arteries of SD rats with hypoxia for one and two weeks were isolated, from which the total RNA were extracted by acid guanidinium thiocyanate-phenol-chlorform .Then the levels of mRNA were measured by RT-PCR. 2) About 3mm-long arterial rings cut from SD rat pulmonary arterial stem were suspended between stainless steelhooks in chamber with warmed (37℃) Kreb's solution. Different concentrations of bFGF were added in a cumulative fashion into the chamber where the rings were suspended. The cumulative concentration response curve was obtained. RESULTS: 1)The levels of bFGF mRNA in pulmonary artery of rats with hypoxia were increased significantly compared with those that without hypoxia (2578±384 counts·min -1 (control) vs 5303±756 (hypoxia) for 1 week and 4054±547 (hypoxia) for 2 weeks, P all <0 05). 2) bFGF at concentrations ranged from 5.56×10 -10 ～2.78×10 -7 mol/L caused dose-dependent contraction of vessel rings of rat pulmonary artery ( r =0 695, P< 0 05), with EC 50 being 2.62×10 -7 mol/L. CONCLUSION: bFGF may play an important role in the hypoxic pulmonary hypertension.