烧伤大鼠小肠肌间神经丛中一氧化氮合酶的组织化学研究

目的　探讨烧伤后大鼠小肠壁内一氧化氮合酶 (NOS)的活性及分布的变化规律。　方法　采用NADPH -黄递酶 (NDP)组织化学法和整装铺片技术对烧伤大鼠小肠壁内NOS的活性及分布进行定量和定位研究。　结果　NOS广泛分布于大鼠小肠壁内 ,主要定位于肌间神经丛。NOS阳性神经元多为圆形和卵圆形 ,神经纤维中多含有膨体 ,形成“串珠”样结构 ,且多与血管和肌纤维伴行。烧伤后肌间神经丛中NOS阳性神经元密度变化不显著 (P >0 .0 5 ) ,但神经元内NOS活性则显著下降(P <0 .0 5～ 0 .0 1) ,同时发现烧伤后NOS阳性神经元结构模糊 ,神经纤维断裂较多 ,未能形成完整的神经纤维网 ,神经纤维中NOS阳性膨体亦明显减少。结论　烧伤后大鼠小肠肌间神经丛中NOS阳性神经结构受损 ,神经元内NOS活性下降 ,同时一氧化氮 (NO)的释放途径亦存在障碍 ,这些变化可能与烧伤后肠道结构受损 ,功能障碍密切相关

Histochemical study on the nitric oxide synthase in the intestinal myenteric plexus of burned rats

OBJECTIVE: To elucidate the postburn change in the activity and the distribution of nitric oxide synthase (NOS) in rat intestinal myenteric plexus. METHODS: The activity and distribution of NOS were quantitatively and locationally studied by histochemical staining with NADPH-diaphorase (NDP), a marker for NOS, and whole mount preparation technique. RESULTS: NOS was widely distributed in whole intestine wall, especially in myenteric plexus. The majority of NOS positive neurons displayed either round or oval shape. There were some varicosities string of bead-like structure in the nerve fibers and which were accompanied by blood vessels and muscular fibers. There was no significant postburn change in the density of NOS positive neurons in myenteric plexus (P < 0.05). Nevertheless the NOS activity of neurons decreased obviously (P < 0.05 similar 0.01). Meanwhile, it was found after injury that there were indistinction of the structure of NOS positive neuron, more breaking of nerve fibers, leading to the lack of integral web of nerve fibers and obvious decrease of NOS positive varicosities in nerve fibers. CONCLUSION: After burn injury, the NOS positive neural structure in myenteric plexus of rat small intestine was damaged with the decrease in NOS activity. Simultaneously, there was impairment of the releasing route of nitric oxide (NO). All these changes might be closely related to intestinal structural damage and dysfunction after burn injury.