黄芪多糖对小鼠免疫细胞信号转导相关分子的影响

为探讨黄芪多糖(APS)免疫调节的作用机理，观察了黄芪多糖对小鼠腹腔巨噬细胞一氧化氮(NO)生成、对体外培养的小鼠脾脏淋巴细胞内游离钙离子水平和蛋白激酶C(PKC)活性的影响。结果显示黄芪多糖能明显促进小白鼠腹腔巨噬细胞NO生成，显著升高小鼠脾淋巴细胞内游离钙离子的水平，引起细胞PKC活性明显升高。提示黄芪多糖通过NO介导信号传递通路，调节脾淋巴细胞内游离钙离子的浓度，升高细胞蛋白激酶活性而影响机体免疫细胞的信号转导，发挥其免疫调节作用。

Effect of Astragalus membranaceus Polysaccharide on Signaling Related Molecules in Murine Immunocytes

This study was carried out to investigate the mechanism of signal transduction in murine immunocytes induced by polysaccharide from Astragalus membranaceus. Nitric oxide (NO) concentrations of murine peritoneal macrophages were examined by a spectrophotometric assay based on the Griess reaction; cytoplasmic free Ca 2+ in murine splenic lymphocytes was measured by a spectroflurometer assay with probe of Fura2-AM. A new ion-pair reversed phase performance liquid chromatograph was used to determine protein kinase C (PKC) activity of spleen lymphocytes in mice. The results showed Astragalus membranaceus polysaccharide increased the production of NO of macrophages and the concentration of intracellular free calcium in splenic cells and activated the PKC of spleen lymphocytes in vitro in mice. In conclusion, Astragalus membranaceus polysaccharide might perform its immunoregulation functions via signal transduction system in immunocytes by activating immunocytes to release NO so as to modulate level of intracellular free calcium and raise the activity of PKC.