活性氧对巨噬细胞呼吸爆发影响及云芝多糖的保护作用

用化学发光法观察到叔丁基氢过氧化物对培养的小鼠腹腔巨噬细胞呼吸爆发有强烈的抑制作用。云芝多糖经腹腔注射后,能增强巨噬细胞呼吸爆发功能对叔丁基氢过氧化物损伤的抵抗力。云芝多糖处理的巨噬细胞谷胱甘肽过氧化物酶基础活力显著提高,在叔丁基氢过氧化物作用下,云芝多糖处理的巨噬细胞仍有较高的谷胱甘肽过氧化物酶活力。说明巨噬细胞的免疫功能与谷胱甘肽过氧化物酶活力有关,非特异性免疫多糖可提高细胞抗氧化能力,减轻活性氧损伤作用。     

降钙素基因相关肽对小鼠肠道集合淋巴结T细胞及腹腔巨噬细…

本工作观察了降钙素基因相关肽（ＣＧＲＰ）对小鼠肠集合淋巴小结（ＰＰ结）Ｔ细胞和小鼠腹腔巨噬细胞功能的影响。结果表明：ＣＧＲＰ能明显抑制ＰＰ结Ｔ淋巴细胞的转化,并且这种作用与Ｔ细胞的分化增殖状态有明显关系。此外ＣＧＲＰ对腹腔巨噬细胞ＤＮＡ和蛋白质的合成也有明显的抑制作用。以上结果提示ＣＧＲＰ可能作为一种抑制型的神经内分泌免疫调节肽而对肠道免疫功能发挥着重要的调节作用。     

降钙素基因相关肽对小鼠肠道集合淋巴结T细胞及腹腔巨噬细胞功能的影响

本工作观察了降钙素基因相关肽（ＣＧＲＰ）对小鼠肠集合淋巴小结（ＰＰ结）Ｔ细胞和小鼠腹腔巨噬细胞功能的影响。结果表明：ＣＧＲＰ能明显抑制ＰＰ结Ｔ淋巴细胞的转化,并且这种作用与Ｔ细胞的分化增殖状态有明显关系。此外ＣＧＲＰ对腹腔巨噬细胞ＤＮＡ和蛋白质的合成也有明显的抑制作用。以上结果提示ＣＣＲＰ可能作为一种抑制型的神经内分泌免疫调节肽而对肠道免疫功能发挥着重要的调节作用。     

云芝提取物对改善小鼠胃肠功能的作用

以大黄水煎剂建立小鼠胃肠功能损害模型,探讨云芝提取物和其中的白桦脂酸对小鼠胃肠功能的影响以及白桦脂酸对小鼠在脂质过氧化方面的影响。研究结果表明云芝提取物和白桦脂酸能够较为显著地提高胃蛋白酶活性,增加胃泌素和胃酸分泌量(P0.01);同时白桦脂酸高低剂量组能够明显降低小鼠血浆中丙二醛的含量,提高超氧化物歧化酶、谷胱甘肽过氧化物酶的活性以及肝脏匀浆中谷胱甘肽过氧化物的含量(P0.01)。说明云芝提取物和白桦脂酸能够有效地改善小鼠的胃肠功能,且抗脂质过氧化是云芝活性成分白桦脂酸治疗作用机制之一。     

异质性荧光染色的巨噬细胞功能研究──Ⅱ．异质性荧光染色的巨噬细胞过氧化物酶活性

细胞化学研究文献报导,巨噬细胞中过氧化物酶的活性有明显的差异,只有部分巨噬细胞过氧化物酶呈阳性反应。本文用淀粉、白喉类毒素和卡介苗分别诱导和活化小鼠腹腔巨噬细胞,进行过氧化物酶反应,并以７６９０－Ｘｕ荧光染液复染后证明,酶反应阳性细胞呈蓝色荧光,而酶反应阴性细胞为淡蓝绿色和黄色荧光。实验表明,过氧化物酶阳性的巨噬细胞是分化程度低的幼稚细胞,因此,过氧化物酶的活性可作为低分化的巨噬细胞的一种标志酶。同时,本文用免疫荧光单克隆抗体间接染色法观察了三种物质诱导和活化的异质性荧光染色的巨噬细胞的分泌功能。     

小麦肽对受环磷酰胺免疫抑制小鼠的免疫调节及抗氧化功能

本研究旨在分析小麦蛋白活性肽对免疫抑制小鼠免疫功能和抗氧化功能的调节作用。小鼠灌胃小麦肽10d,第8天用环磷酰胺诱导免疫抑制,测定血清溶血素、抗体生成细胞含量、脾细胞增殖、体外腹腔巨噬细胞吞噬能力、肝脏抗氧化酶活性和丙二醛(MDA)含量以及血清清除DPPH和·OH的能力。实验结果表明,环磷酰胺处理显著的降低了小鼠血清中抗SRBC抗体(溶血素HC50)水平和腹腔巨噬细胞的吞噬能力;同时伴随着肝脏超氧化物歧化酶活性(SOD)、过氧化氢酶活力(CAT)、总抗氧化能力(T-AOC)的降低和MDA含量的提高。给小鼠灌胃小麦肽可以恢复HC50和脾细胞增殖,显著提高抗体生成细胞含量和腹腔巨噬细胞吞噬能力;此外,小麦肽增强了小鼠血清清除DPPH和清除·OH的能力。以上结果表明,小麦肽可以调节应激状态引起的机体抗氧化体系紊乱及免疫功能的降低。这可能与小麦肽缓冲自由基生成、激活腹腔巨噬细胞和脾淋巴细胞活性有关。     

鳞柄小奥德蘑多糖对巨噬细胞免疫功能的调节作用

研究鳞柄小奥德蘑多糖对小鼠巨噬细胞的免疫调节作用。采用灌洗腹腔法收集小鼠巨噬细胞,建立其体外培养体系;采用鸡血红细胞法、荧光探针标记、总一氧化氮检测和酶联免疫吸附试验等方法分别检测巨噬细胞吞噬能力、NO合成量、肿瘤坏死因子-α、白细胞介素-1、白细胞介素-6和白细胞介素-12等的分泌量。结果显示,与空白对照组相比,鳞柄小奥德蘑多糖能显著增强体外培养和腹腔内巨噬细胞的吞噬能力和NO合成量,增加体外培养的小鼠巨噬细胞对肿瘤坏死因子-α、白细胞介素-1、白细胞介素-6和白细胞介素-12等细胞因子的分泌量。因此,鳞柄小奥德蘑多糖可能通过提高细胞对NO和多种免疫相关信号分子的分泌量,增强细胞的吞噬能力,进而调节小鼠巨噬细胞的免疫功能。     

红毛五加多糖不同组分对小鼠腹腔巨噬细胞免疫功能的研究

本文研究红毛五加多糖不同组分(AHP-I、AHP-II、AHP-III)对小鼠腹腔巨噬细胞免疫调节功能的影响,为进一步阐明红毛五加多糖对小鼠免疫调节作用机制奠定基础。采用不同浓度的3种多糖组分作用于小鼠腹腔巨噬细胞,测定其对巨噬细胞吞噬中性红、释放NO能力、分泌IL-6、TNF-α、IL-1β水平的影响。最后结果是红毛五加多糖的3种不同组分对小鼠免疫细胞有不同的刺激能力。其中,AHP-II可极其显著地增强吞噬细胞的吞噬功能,促进其合成NO,促进巨噬细胞细胞因子的分泌。因此红毛五加多糖能激活小鼠腹腔巨噬细胞,其中,AHP-II是最重要的作用组分。     

蜜环菌多糖对小鼠腹腔巨噬细胞免疫功能的影响

从蜜环菌菌索提取的多糖（ＭＨＧ）能在体外显著增强小鼠腹腔巨噬细胞吞噬中性红的作用,并可诱生巨噬细胞产生一氧化氮。在高浓度时,对巨噬细胞分泌ＩＬ－１有一定的作用。     

抗氧化干预对肝癌细胞增殖及N—ras基因表达的作用

探讨了抗氧化剂抑制肿瘤块生长、促进癌细胞凋亡作用。在昆明小鼠皮下接种肝癌细胞悬液,同时灌服各种抗氧化剂维生素E、β胡萝卜素、谷氨酰胺、硒酸酯多糖、云芝多糖,有不同程度抑制肿瘤块生长作用,后两种多糖抗氧化剂具有促进非特异性免疫能力提高和血浆中NO含量增高,并增强对肿瘤的抑制作用。在7721人肝癌细胞株中,加入以上各种抗氧化剂,能不同程度抑制癌细胞增殖并促使细胞凋亡,与此同时,小鼠血浆中从胱甘肽过氧化物酶（GSH－Px）活力提高、丙二醛（MDA）含量下降。低浓度过氧化氢可促进癌细胞增殖,高浓度可促使细胞凋亡或坏死。其可能的机制一是阻断自由基对癌细胞增殖的信号转导,抑制N－ras癌基因表达;同时,Mn-SOD、c-fos、c-jun mRNA表达提高。二是通过提高非特异性免疫能力促进NO释放,直接抑制癌细胞生长。     

L929 cell conditioned medium protects RAW264.7 cells from oxidative injury through inducing antioxidant enzymes

We have previously found that L929 cell conditioned medium (L929-CM) could protect mouse peritoneal macrophages from oxidative injury. To uncover the mechanism further, we investigated the effect of L929-CM on the oxidative injury caused by tbOOH to RAW264.7 cell lines. The results showed that L929-CM could protect RAW264.7 cells from oxidative injury (presented by cell morphology and cell survival rate), and L929-CM could also improve total superoxide dismutase (SOD), selenium-dependent and non-selenium-dependent glutathione peroxidase (SeGPx and non-SeGPx) activities in RAW264.7 cells. RT-PCR analysis showed that, L929-CM could induce plasma glutathione peroxidase (PLGPx) mRNA expression, while there was no inducing effect of L929-CM on phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA expression in RAW264.7 cells. 5 microg/ml actinomycin D, 30 microg/ml cycloheximide (de novo protein synthesis inhibitor) and 50 microg/ml acetovanilone (intracellular superoxide anion production inhibitor) had no effects in attenuating the induction of PLGPx expression by L929-CM.     

Effects of selenium and serum on selenoprotein W in cultured L8 muscle cells

When rat L8 muscle cells were cultured to examine the effects of serum and selenium concentration on selenoprotein W levels and glutathione peroxidase (GPX) activities, no significant differences (P > 0.05) were found in selenoprotein W levels and GPX activities during differentiation. With three different forms of selenium, selenoprotein W levels and GPX activities were shown to increase in L8 myotubes cultured in media with these selenocompounds. Selenite was utilized more efficiently than selenocysteine for both selenoprotein W and GPX activity, but selenium as selenomethionine was less available. Both the protein content and mRNA levels for selenoprotein W were affected by the selenium content of the media. Northern blot data indicated that the expression of selenoprotein W mRNA increased significantly when L8 myotubes were cultured with selenium (P > 0.05). L8 myotubes cultured in 10% calf serum (CS) versus 2% CS with or without addition of 10 m selenium indicated that the increase of selenoprotein W level in L8 myotubes cultured with higher serum concentration (10% CS) is due to the higher selenium concentration in media rather than serum itself.     

Antagonistic effect of scutellarin on the toxicity of selenium in rat livers

Selenium has both nutritional function and toxicity according to its concentration and species. To counteract the toxicity of selenium, scutellarin was investigated. Wistar rats were supplemented with 40 μg Se/kg/d as sodium selenite, 40 μg Se/kg/d with 20 mg/kg/d scutellarin, and 20 mg/kg/d scutellarin, respectively, for 15 d. The mRNA levels and activities of glutathione peroxidase (GSH-Px) and thioredoxin reductase (TR), and the malondialdehyde (MDA) contents were measured. Reactive oxygen species (ROS) were detected by chemiluminescence assay, and tissue conformation was investigated by histological study. The results showed significant decreases of mRNA levels and activities of GSH-Px and TR and a significant increase of MDA content in livers of the Se-treated rats (p<0.05, compared with the control). Supplementation of scutellarin to the Se-treated group significantly inhibited the decreases of mRNA levels and activities, and the increase of MDA content (p<0.05, compared with the Setreated group). Meanwhile, scutellarin-scavenged ROS generated in the mixture of sodium selenite, reduced glutathione, and oxygen. Liver injury was displayed in slices exposed to selenium at the present dose. The groups treated with both selenium and scutellarin or only scutellarin did not show significant tissue damage. Thus, scutellarin had an antagonistic effect against the toxicity of selenium.     

硒性白内障大鼠模型晶状体中GR和GSH-Px的表达

 为探讨硒性白内障大鼠晶状体中谷胱甘肽过氧化物酶 (GSH Px)和谷胱甘肽还原酶 (GR)的活性调节在硒性白内障形成中的作用及调节方式 ,采用半定量RT PCR方法 ,比较正常晶状体、核中心混浊晶状体 (核白 )和完全混浊晶状体 (全白 )中GSH Px和GR的mRNA水平及酶活性的变化 .研究发现 ,核白晶状体中 2种酶的活性和mRNA水平均升高 ,其中酶活性的升高幅度小于mRNA水平 .随着白内障的发展 ,2种酶的活性和mRNA水平均逐渐下降 .至晶状体全白时 ,2种酶的活性均显著低于正常 ;全白时GR的mRNA水平降至正常 ,GSH Px的mRNA水平则仍高于正常 .结果表明 ,硒性白内障形成与细胞内GSH Px和GR的活性调节密切相关 ,GSH Px和GR的活性调节可能主要发生在转录水平     

A comparative study on effect of dietary selenium and vitamin E on some antioxidant enzyme activities of liver and brain tissues

Since selenium and vitamin E have been increasingly recognized as an essential element in biology and medicine, current research activities in the field of human medicine and nutrition are devoted to the possibilities of using these antioxidants for the prevention or treatment of many diseases. The present study was aimed at investigating and comparing the effects of dietary antioxidants on glutathione reductase and glutathione peroxidase activities as well as free and protein-bound sulfhydryl contents of rat liver and brain tissues. For 12–14 wk, both sex of weanling rats were fed a standardized selenium-deficient and vitamin E-deficient diet, a selenium-excess diet, or a control diet. It is observed that glutathione reductase and glutathione peroxidase activities of both tissues of the rats fed with a selenium-deficient or excess diet were significantly lower than the values of the control group. It is also shown that free and bound sulfhydryl concentrations of these tissues of both experimental groups were significantly lower than the control group. The percentage of glutathione reductase and glutathione peroxidase activities of the deficient group with respect to the control were 50% and 47% in liver and 66% and 61% in the brain, respectively; while these values in excess group were 51% and 69% in liver and 55% and 80% in brain, respectively. Free sulfhydryl contents of the tissues in both experimental groups showed a parallel decrease. Furthermore, the decrease in protein-bound sulfhydryl values of brain tissues were more pronounced than the values found for liver. It seems that not only liver but also the brain is an important target organ to the alteration in antioxidant system through either a deficiency of both selenium and vitamin E or an excess of selenium alone in the diet.     

A Simultaneous Visualization of the Antioxidant Enzymes Glutathione Peroxidase and Catalase on Polyacrylamide Gels

A simple and sensitive method for the simultaneous visualization of glutathione peroxidase and catalase on polyacrylamide gels is described. The procedure included: (I) running samples on a 7. 5% polyacryla-mide gel, (2) soaking the gel in a certain concentration of reduced glutathione (0.25-2.0 mM). (3) soaking the gel in GSH plus H_zO_z or cumene hydroperoxide, (4) finally staining with a 1% ferric chloride I% potassium ferricyanide solution. The best concentration of glutathione for simultaneous visualization of glutathione peroxidase and catalase was 0.25rnM; I.5mM glutathione was the best concentration for visualization of glutathione peroxidase alone. The method is sensitive enough to detect catalase and glutathione peroxidase in mouse liver homogenates and also it is specific for glutathione peroxidase since other peroxidases such as lactoperoxidase, horseradish peroxidase and glutathione S-transferase cannot be visualized. Using this method, it was found that unlike catalase. glutathione peroxidase is heat resistant (68°C. 1min), but sensitive to 10mM sodium iodoacetate.