中文摘要：

【目的】研究羊驼皮肤毛囊中一氧化氮合酶（nitric oxide synthases,NOS）的存在差异。【方法】Dopa染色定位黑色素细胞;利用免疫组化和免疫印迹技术对不同毛色羊驼皮肤毛囊中NOS进行定位与定量分析,分析NOS在不同毛色羊驼皮肤毛囊中表达的差异。【结果】Dopa染色显示黑色素细胞存在于羊驼毛囊鞘和毛乳头中。免疫组化结果显示3种NOS在白毛组和棕毛组皮肤毛囊中均有阳性产物。NOS1和NOS3表达呈弱阳性,NOS2表达呈强阳性;NOS1在毛乳头细胞无阳性产物,在白毛组毛囊鞘细胞与棕毛组无显著差异（P〉0.05）;NOS2在棕毛组毛囊鞘细胞与白毛组无显著差异（P〉0.05）,在棕毛组毛乳头细胞极显著高于白毛组（P〈0.01）;NOS3在毛囊鞘细胞无阳性产物,在白毛组毛乳头细胞与棕毛组无显著差异（P〉0.05）。免疫印迹显示NOS2在棕毛组显著高于白毛组（P〈0.05）。【结论】NOS2参与调节羊驼毛色形成,为NO信号调节羊驼毛色形成机制的研究提供试验数据。

英文摘要：

【Objective】 The experiment was made to study the relation of alpaca coat color and the expression of nitric oxide synthases （NOS） in alpaca skin. 【Method】 The relationship between the alpacas coat color and the expression of NOS was studied by determining the expression and localization of NOS in alpaca skin with different hair colors. The protein expression of NOS was determined by western blotting. The tissue localization of NOS was examined by immunohistochemistry. 【Result】 There was a positive expression of three NOS in skin of white alpaca group and brown alpaca group,the expression in hair follicle tissue significantly higher than peripheral connective tissue （P〉0.05）. In hair follicle tissue of white alpaca group and brown alpaca group,the expression of NOS1 and NOS3 showed a weak positive,NOS2 showed a strong positive. The expression of NOS2 in hair follicle tissue of white alpaca group was significantly lower than those in brown alpaca group （P〉0.05）. The expression of NOS1 and NOS3 showed no significant difference in hair follicle tissue of white alpaca group and brown alpaca group （P〈0.01）. The expression of three NOS showed no significant difference in connective tissue （P〉0.05）. Western blotting showed that the expression of NOS2 in white alpaca group was significantly lower than those in brown alpaca group （P〈0.05）.【Conclusion】This is the first study on the expression of NOS in alpaca skin with different coat colors,three NOS main expression in hair follicle site. The expression of NOS1 and NOS3 is not related with coat color; the expression of NOS2 in hair follicle is related with coat color. The experiment has laid a foundation for further study on the effect of nitric oxide signal on melanin production.