单侧膈神经切断对幼猪肺内表皮生长因子及角质细胞生长因子基因表达的影响

INFLUENCE OF EXPRESSION LEVELS OF EPIDERMAL GROWTH FACTOR AND KERATINOCYTE GROWTH FACTOR AFTER UNILATERAL PHRENECTOMY IN PIGLETS

目的研究膈神经切断后幼猪肺内表皮生长因子(epidermal growth factor,EGF)mRNA及角质细胞生长因子(keratinocyte growth factor,KGF)mRNA表达的变化及其意义。方法健康雄性幼猪36只,按手术时日龄10、30和50d分为三组,每组12只,再随机分为实验组(膈神经切断,n=6)和对照组(n=6)。实验组于颈部将左侧膈神经切断,对照组仅行左侧膈神经暴露。分别于术后2周处死动物,采用RT-PCR方法对肺组织中EGF及KGF mRNA的表达水平进行检测分析。结果RT-PCR的融解曲线示EGF、KGF和内参基因GAPDH分别在80.0、84.5和89.0℃附近各有一单峰,融解温度均一。单侧膈神经切断术后2周,10d和30d实验组幼猪肺内EGF mRNA相对表达水平分别为3.53±0.36和1.73±0.29,KGF mRNA的相对表达水平为4.71±0.42和2.77±0.29,均较相同日龄对照组(EGF mRNA表达水平4.60±0.41、2.18±0.24和KGF mRNA表达水平6.05±0.42、3.58±0.31)低,比较差异有统计学意义(P<0.05);50d实验组幼猪肺内EGF及KGF mRNA的表达水平(0.72±0.15和1.83±0.22)与对照组(0.74±0.18和2.09±0.23)比较差异无统计学意义(P>0.05)。对照组间比较显示幼猪肺内EGF及KGF mRNA的表达水平差异有统计学意义(P<0.01),随幼猪年龄增长肺内EGF及KGF mRNA的表达水平下降。结论单侧膈神经切断将导致术时日龄<30d幼猪肺内生长因子表达水平的下降,进而影响肺组织的正常发育,提示年龄较小的患儿应慎行膈神经移位术。

Objective To investigate the different influence of the expression levels of the epidermal growth factor （EGF） and the keratinocyte growth factor （KGF） after the unilateral phrenectomy in piglets. Methods Thirtysix piglets were divided into 3 groups according to their ages during the operation （10 d, 30 d, 50 d）. In each group, 6 piglets underwent the left cervical phrenectomy and 6 piglets were used as the sham-operation controls. The expression levels of EGF and KGF were determined by the real time quantitative RT-PCR at 2 weeks after operation. Results The melting curves of RT-PCR showed that there was a single peark at the temperature of 80.0, 84.5 and 89.0 C of EGF,KGF and GAPDH, respectively. In the experimental group, the expression levels of EGF were 3.53±0. 36 and 1.73±0. 29, and the expression levels of KGF were 4. 71±0. 42 and 2.77±0.29 in the piglets undergiong the operation at their ages of 10 d and 30 d. Compared with the control group,the expression levels of EGF （4.60±0.41, 2.18 ± 0. 24） and KGF （6.05 ± 0.42,3.58 ± 0. 31 ） showed that there was a significant decrease postoperatively in the piglets undergoing the operation at their ages of 10 d and 30 d（P〈0. 05）. However, there was no significant change in the piglets undergoing the operation at their ages of 50 d（P〉0.05）. The expression levels of EGF and KGF were significantly decreased with the lung development of the piglets（P〈0. 05）. Conclusion The unilateral phrenectomy performed in the piglets younger than 30 d may cause abnormity of the EGF and KGF expression levels. The piglets older than 50 d may not cause a significant influence.