针刺对备用DRG的NGF及其mRNA阳性大、中、小神经元数量的影响

本研究观察了 NGF及其 m RNA阳性神经元在 DRG大、中、小神经元中的数量变化 ,目的在于探讨 DRG各类神经元NGF变化与针刺促进脊髓可塑性的关系。对 5只成年猫进行双侧备用根手术。术后当日开始针刺一侧 L6 脊神经后肢分布区的两组穴位即足三里和悬中、伏兔和三阴交 ,每天一次 ,每次 3 0 min,连续针刺 7d后处死动物。取针刺侧与非针刺侧 L6 的 DRG制成 2 0μm厚冰冻纵切片。分别用 NGF抗血清和 NGF的 c RNA探针进行免疫组织化学反应及原位杂交染色。计数两侧 DRG相同面积内大 (>5 7μm)、中 (4 2～ 5 7μm)、小 (<42 μm)型 NGF及其 m RNA阳性神经元的数量。结果显示 :针刺侧备用 DRG NGF及其 m RNA阳性大、小型神经元的数量明显增加 (P<0 .0 5 ) ,而对中型神经元数量影响不明显。结论 :针刺促进脊髓可塑性可能与备用 DRG大、小神经元表达 NGF增多有关。

THE EFFECT OF ACUPUNCTURE ON THE EXPRESSION OF NGF IN LARGE, MEDIUM AND SMALL SIZED NEURONS FOLLOWING PARTIAL DORSAL ROOT RHIZOTOMY

In order to explore the change on expression of NGF in large, medium and small sized neurons of spared DRG following acupuncture, five adult cats were performed bilateral partial dorsal root rhizotomy (L 1～L 5, L 7～S 2 DRG were sectioned, but L 6 was spared). Two groups of points (Zu San Li and Xuan Zhong, Futu and San Yin Jiao) located in one side of hind limb were electro stimulated for thirty minutes every day. At 7th day after acupuncture, the spared dorsal root ganglions (L 6) were taken and made into frozen sections 20 μm in thickness. Immunohistochemistry (NGF antibody 1∶100) and in situ hybridization (NGF cRNA probe 1∶100) techniques were used. The numbers of positive neurons for NGF and its mRNA in large, medium and small sized neurons of L 6 DRG were counted in the same acre, respectively. The results showed that the numbers of positive large neurons for NGF and its mRNA in DRG of acupuncture side increased apparently than that of unacupuncture side (P<0.05). But the number of medium neurons of L 6 DRG did not change prominently. The results indicate that the increase in expression of NGF in large and small sized neurons of spared DRG may be involved in the spinal cord plasticity promoted by acupuncture.