宫内发育迟缓对大鼠脑内NGF及TrkA表达影响的研究

Expression of NGF and TrkA in the brain of rats with intrauterine growth retardation

目的观察神经生长因子(NGF)及酪氨酸激酶受体A(TrkA)在宫内发育迟缓(IUGR)大鼠脑不同发育阶段的变化,探讨IUGR大鼠脑发育迟缓的机制。方法 32只孕鼠随机分成IUGR组和正常对照组。采用孕期全程低蛋白饮食的方法建立IUGR大鼠模型。各组仔鼠于生后0 d、7 d、14 d、21 d断头取脑,免疫组织化学及Western blot方法检测脑中NGF和TrkA蛋白的表达情况。结果免疫组化及Western blot结果均显示低蛋白饮食组0 d、7 d、14 d、21 d仔鼠脑内NGF及TrkA蛋白的表达均较正常组显著降低,差异有统计学意义(P<0.01)。结论脑内NGF及TrkA蛋白表达的降低可能是IUGR大鼠脑发育迟缓发生的机制之一。

Objective To study the mechanism of brain development delay in rats with intrauterine growth retardation（IUGR） by examining the expression of nerve growth factor（NGF） and tyrosine kinase receptor A（Trk A） in the brain.Methods Thirty-two pregnant rats were randomly fed with a normal diet（control group） or lower protein diet（IUGR group） during pregnancy（n=16 each）.The pup rats were sacrificed at 0,7,14 or 21 days after birth.The protein levels of NGF and TrkA in the brain were determined by Western blot and immunohistochemistry staining.Results The levels of NGF and TrkA in the brain in pup rats of the IUGR group were significantly lower than those in the control group 0,7,14 and 21 days after birth.Conclusions The decreased expression of protein levels of NGF and TrkA in the brain might be one of the causes of brain development delay in IUGR rats.