细胞微环境的稳定是保持细胞正常增殖、 代谢和功能活动的重要条件, 微环境成分的异常变化可使细胞发生病变。 采用荧光光谱技术研究离体白细胞在多糖微环境中荧光发射特性的变化规律和发光机制, 并进一步的分析了多糖对白细胞的生物活性的影响。 实验结果表明: 当白细胞受波长为407 nm的激光照射时, 发射位于450 nm的荧光。 在加入脂多糖或葡聚糖时, 白细胞的荧光发射峰的位置不会变化, 峰值受到影响。 脂多糖的加入会减弱白细胞荧光峰强度, 且荧光强度随脂多糖浓度（0～500 μg·mL-1范围内）的增加而持续减弱。 而葡聚糖可以一定程度增加白细胞的荧光强度, 浓度越高, 荧光强度越大。 分析认为白细胞发射的450 nm荧光来自发射物质烟酰胺腺嘌呤二核苷酸(NADH)。 白细胞内NADH随着离体时间的增长, 被氧化成不发荧光的烟酰胺腺嘌呤磷酸二核苷酸（NAD+）, 导致细胞荧光峰值下降, 从而引起细胞凋亡。 加入脂多糖产生的羟自由基（·OH）会与NADH发生氧化反应, 因此脂多糖加速了NADH的消耗, 导致白细胞荧光减弱, 加快细胞凋亡。 而葡聚糖主要是由葡萄糖单体组成, 葡聚糖的加入会将NAD+还原成NADH, 因此延缓了白细胞的凋亡。 分析认为脂多糖可以加速白细胞的凋亡, 提高细胞发生炎症甚至是肿瘤的机率, 而葡聚糖对白细胞有保护作用。 该研究为研究肿瘤的发生和发展过程以及治疗提供有价值的参考。

The stability of the cell microenvironment is an essential condition to maintain healthy cell proliferation, metabolism, and functional activities, and the abnormality of microenvironment components can cause pathological cell changes. In this paper, the fluorescence emission characteristics and mechanism of white blood cell (WBC) in vitro in polysaccharide microenvironment were considered by fluorescence spectroscopy, and the effect of Polysaccharide on the WBC biological activity was further analyzed. The results showed that under 407 nm laser irradiation, white blood cells emit fluorescence at 450 nm. When lipopolysaccharide or dextran is added, the position of fluorescence emission peak of leukocyte will not change, but the fluorescence peak will be affected. The addition of lipopolysaccharide (LPS) can weaken the fluorescence peak intensity of leukocytes, and the higher the LPS concentration (in the range of 0～500 μg·mL-1), the lower the fluorescence intensity. While the addition of dextran can enhance the WBC fluorescence intensity to a certain extent, and the higher the concentration, the stronger the fluorescence. It believes that the 450 nm fluorescence emitted by WBC comes from the nicotinamide adenine dinucleotide (NADH). NADH is oxidized to NAD+ with the increase of cell in vitro, which leads to the decrease of fluorescence intensity and apoptosis. The hydroxyl radical (·OH) generated by adding lipopolysaccharide will react with NADH. Therefore, lipopolysaccharide accelerates the consumption of NADH, resulting in weakened leukocyte fluorescence and accelerated cell apoptosis. Dextran is mainly composed of glucose monomer, which can reduce NAD+ to NADH, thus delaying the WBC apoptosis. It believes that lipopolysaccharide can accelerate the WBC apoptosis, improve the probability of inflammation and even tumor, while dextran can protect WBC. This study is used as a valuable reference for the study of tumor occurrence, development, and treatment.