手汗症患者胸交感神经干脑源性神经营养因子和神经调节因子-1基因表达与有髓神经纤维密度及横截面积的关系

目的 观察手汗症患者胸交感神经干脑源性神经营养因子(BDNF)和神经调节因子-1(NRG-1)基因表达及对有髓神经纤维密度和单个纤维横截面积的影响,探讨与手汗症发病机制的关系.方法 采用核固红-固绿髓鞘染色法显示有髓神经纤维,通过显微图像分析系统观察30例手汗症患者T3胸交感神经干有髓神经纤维密度和单个有髓神经纤维的横截面积,以及用逆转录-聚合酶链反应(RT-PCR)法检测BDNF和NRG-1基因表达强度,并与8例非手汗症患者进行对照研究.结果 手汗症患者T3胸交感神经干中有髓神经纤维密度和单个有髓神经纤维的横截面积较非手汗症患者明显增高(t=7.023,P<0.05;t=7.462,P<0.05);BDNF和NRG-1基因在手汗症患者T3胸交感神经干中mRNA水平的相对表达强度比值分别为1.17600±0.028 70、1.216 10±0.075 39,较非手汗症患者的比值1.037 50±0.053 79、1.042 70±0.043 57明显增高(t=9.940,P<0.05;t=6.195,P<0.05).结论 BDNF和NRG-1基因表达强度增高促使胸交感神经干的有髓神经纤维密度增高以及单个有髓神经纤维的横截面积增大,从而导致胸交感神经传导速度增快、兴奋性增高,可能为手汗症的发病基础之一.

Relationship between genetic expression of BDNF and NRG-1 and myelinated nerve fiber density and cross-sectional area in thoracic sympathetic trunk of palmar hyperhidrosis

Objective To investigate the gene expression of brain-derived neurotrophic factor ( BD-NF) and neuregulin-1 (NRG-1) in thoracic sympathetic trunk and their relation to myelinated nerve fiber density and single myelinated nerve fibers cross-sectional area in palmar hyperhidrosis. Methods Fast red-fast green myelin sheath staining was used to show myelinated nerve fibers. Using the micro-image analysis system,30 cases of myelinated nerve fiber density and single myelinated nerve fibers cross-sectional area were observed in T3 thoracic sympathetic trunk of patients with palmar hyperhidrosis. BDNF and NRG-1 gene expression was also analyzed by RT-PCR. Eight cases of non-palmar hyperhidrosis patients served as controls. Results In 33 thoracic sympathetic trunk of patients with palmar hyperhidrosis, myelinated nerve fiber density and single myelinated nerve fibers cross-sectional area were significantly increased as compared with controls (t = 7. 023,P < 0.05 ; t = 7.462, P < 0.05 respectively). The expression of BDNF and NRG-1 in 33 thoracic sympathetic trunk of patients with palmar hyperhidrosis was 1. 176 00 ± 0.028 70,1. 216 10± 0.075 39 respectively, and that in control group was 1. 037 50 ± 0.053 79,1. 042 70 ± 0.043 57 respectively. The former was significantly higher than the latter ( t = 9.940,P < 0.05 ; t = 6. 195. P < 0.05 respectively). Conclusion BDNF and NRG-I gene over expression increased myelinated nerve fiber density and single myelinated nerve fibers cross-sectional area of thoracic sympathetic trunk in patients with palmar hyperhidro-sis. Thus transmission speed and ability of excitatory of thoracic sympathetic nerve were also increased, which may play a role in the pathogenesis of palmar hyperhidrosis.