切断L_(4)背根对脊髓板层一氧化氮合酶表达的影响

The Effect of Axotomy on the Expression of NOS in Spinal Lamina Ⅱ of L_4 Segment

为探讨背根切断对脊髓 板层一氧化氮合酶 (NOS)的影响 ,采用 NADPH- d酶组织化学方法 ,观察了切断 L4背根 7天后脊髓 板层 NOS的分布及变化。结果 :NOS主要分布于脊髓 板层的神经膨体及少数神经元胞浆内。切断背根 7天后 ,手术侧 L4脊髓 板层 NOS的平均灰度较非手术侧明显增加 (P<0 .0 5 ) ,神经膨体密度则较非手术侧明显减少 (P<0 .0 1) ,表明切断背根可致相应节段脊髓 板层 NOS含量明显减少。提示由 NOS产生的一氧化氮 (NO)可能在背根切断后脊髓 板层的病理过程中发挥作用。

This study sought to explore the effect of axotomy on the expression of nitric oxide synthase (NOS) in spinal lamina Ⅱ of L 4 segment. Five tomcats were subjected to axotomy, and 7 days later the distribution and change of NOS in their spinal lamina Ⅱ (L 4) were studied with nicotinamide adenosine dinucleotide phosphate diaphorase (NADPH d) reaction. The average gray degree and the number of varicosity of NOS in spinal lamina Ⅱ were measured and counted respectively. The NOS positive product was found mainly distributed in axonal terminal,varicosities and a few neurons in spinal lamina Ⅱ . The average gray degree of NOS increased apparently on the operated side as compared with that on the unoperated side ( P <0 05). The number of NOS positive varicosites on the operated side was significantly smaller than that on the unoperated side ( P <0 01). The results demonstrated that the level of NOS in lamina Ⅱ following axotomy was downregulated greatly, suggesting that nitric oxide (NO) derived NOS may play an important role in spinal lamina Ⅱ under pathological condition.