富硒平菇和亚硒酸钠对老年大鼠有关指标的影响

目的　探讨有关硒对老年大鼠 (18月龄 )凝血和纤溶功能有关指标的影响以及富硒平菇和亚硒酸钠对老年鼠合适的补充剂量 ,并比较富硒平菇和亚硒酸钠的优劣。方法　对 18月龄老年鼠进行实验 ,实验期12 3d ,分别观察添加亚硒酸钠或富硒平菇干粉的饲料 (含硒量为 0 2、0 2 5、0 4、0 6mg/kg)对血浆血栓素、前列环素、D 二聚体 (DD)、谷胱甘肽过氧化酶 (GSH PX)、超氧化物歧化酶 (SOD)、脂质过氧化物 (LPO)以及丙氨酸转氨酶(ALT)和实验前后体重变化的差异。结果　适量硒 0 2mg/kg饲料 ,补硒 0 4mg/kg饲料 ,对于老年大鼠前列环素 (PGI2 )含量的增高有促进作用 ,对血栓素A2 (TXA2 )有降低作用 ,对于PGI2 /TXA2 的比值和GSH PX活性的提高及LPO的降低均有促进作用。 0 6mg/kg饲料不能降低PGI2 /TXA2 的比值 ,并能造成D D含量增高和ALT活性有所提高 ,0 6mg/kg饲料组亚硒酸钠还能引起老年鼠体重下降 ,结果还提示富硒平菇优于亚硒酸钠。 结论　补硒应当慎重。     

汉防己甲素对四氧嘧啶致大鼠血清LPO含量及全血GSH—P_x活性改变的影响

本实验观察了静脉注射四氧嘧啶(50mg/kg)前1.5h腹腔注射汉防己甲素(100mg/kg)对四氧嘧啶致血清LPO含量及全血GSH—Px活性变化的影响。实验结果表明,四氧嘧啶于给药后24h可使血清LPO含量明显升高(P<0.01),全血GSH—Px活性明显降低(P<0.01);而预防性注射汉防己甲素则可预防四氧嘧啶引起的血清LPO含量升高,并对全血GSH—Px活性有明显的保护作用。     

低硒富锰和大鼠心肌损伤的关系研究

目的：观察硒、VitE、锌单因素及复合因素对心肌损伤的影响。方法：用低硒富锰人工半合成饲料喂大白鼠8周，复制动物心肌损伤模型。并补充硒（0．3mg/kg）或VitE(250mg/kg）或锌（200mg/kg），观察相关情况。结果：单因素硒、VietE、锌及复合因素均可使血清谷胱甘肽过氧化物酶（GSH－Px）活性提高，使心肌组织脂质过氧化物LPO值明显降低，心肌坏死检出率有降低的趋势。结论：复合因素好于单因素，三因素明显好于双因素。     

维生素C和亚硒酸钠对大鼠肝脏细胞色素P448的抗诱导作用

化学致癌剂4,4’-亚甲基双(2-氯苯胺)[MOCA]可明显诱导雄性大鼠肝脏乙氧基异吩噁唑O-脱乙基酶[EROD]活性,该酶为细胞色素P448的标准酶。在用MOCA染毒前一小时腹腔注射维生素C(650mg/kg)或亚硒酸钠(1mg/kg),均可明显抑制EROD活性的诱导。连续经口灌胃给维生素C(150mg/kg)或亚硒酸钠(0.5mg/kg)三周,也可明显抑制MOCA对大鼠肝脏EROD活性的诱导。提示两种药物对化学致癌物在体内的代谢活化过程有干扰作用。     

茶酚硒混合物的小鼠急性毒性试验

目的:观察茶多酚(TP)与亚硒酸钠(sodium selenite)混合物一次给予小鼠的急性毒性反应和死亡情况.方法:一次灌胃(ig)给药,观察14d.结果:测得TP单用一次ig的LD50为2914.45mg/kg;亚硒酸钠单用一次ig的LD50为33.54mg/kg;当TP与亚硒酸钠按7997.3mg∶2.7mg比例做成混合物,测得混合物单次ig的LD50为2510.29mg/kg,其中亚硒酸钠的含量为0.85mg/kg.结论:茶酚硒混合物单次ig的LD50为2510.29mg/kg.     

茶酚硒混合物的小鼠急性毒性试验

目的:观察茶多酚(TP)与亚硒酸钠(sodium selenite)混合物一次给予小鼠的急性毒性反应和死亡情况.方法:一次灌胃(ig)给药,观察14d.结果:测得TP单用一次ig的LD50为2914.45mg/kg;亚硒酸钠单用一次ig的LD50为33.54mg/kg;当TP与亚硒酸钠按7997.3mg∶2.7mg比例做成混合物,测得混合物单次ig的LD50为2510.29mg/kg,其中亚硒酸钠的含量为0.85mg/kg.结论:茶酚硒混合物单次ig的LD50为2510.29mg/kg.     

二硫化碳对大鼠血液及心肌主动脉中LPO和SOD的影响

本文报告CS_2亚慢性染毒大鼠血液、心肌和主动脉中脂质过氧化物(LPO)含量和超氧化物歧化酶(SOD)活性测定的结果。实验分四组:高剂量组,320mg/kg;低剂量组,160mg/kg;溶剂对照组;橄榄油;对照组,生理盐水。每日腹腔注射,连续35天。处死动物,制备血液及心肌、主动     

肺癌患者化疗前后血清SOD、LPO、GSH—PX水平的变化及临床意义

目的探讨肺癌患者化疗前后血清SOD、LPO、GSH—PX含量的变化及意义。方法应用放射免疫分析法和生化法对31例肺癌患者进行了化疗前后血清SOD、LPO、GSH—PX含量的检测，并与35名正常人作比较。结果肺癌患者化疗前血清SOD、GSH—PX水平明显低于正常人组（P〈O．01），而LPO则明显高正常人组（P〈0．01），化疗后6个月复发者SOD、LPO、GSH—PX水平持续异常，未复发者SOD、LPO、GSH—PX水平接近正常。结论观察肺癌患者血清SOD、LPO、GSH—PX含量的变化与患者的预后密切相关。     

灯盏花素的抗氧化作用及拮抗硒对大鼠肝脏毒性的研究

目的　探讨灯盏花素对人类允许的最高摄入量 (UL upperlimitofintake)硒所致毒性的拮抗作用。 方法　采用体外化学发光法测定灯盏花素清除亚硒酸钠 (Na2 SeO3)产生的活性氧自由基 (ROS)的能力、动物模型研究灯盏花素对大鼠肝脏丙二醛 (MDA)含量、抗氧化酶活性及组织病理学损伤的影响。结果　体外实验表明灯盏花素能有效清除由Na2 SeO3产生的ROS。动物实验中补UL硒及灯盏花素组大鼠肝脏MDA含量低于仅补UL硒组 ;超氧化物歧化酶(SOD)、过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GSH Px)活性高于仅补UL硒组 ;肝组织切片显示受损伤程度与仅补UL硒组相比减轻。结论　灯盏花素能有效拮抗UL硒所致的毒性 ,其机制与灯盏花素清除硒产生的ROS的作用有关     

N-乙酰半胱氨酸和亚硒酸钠对镉亚慢性毒性的影响

目的探讨N-乙酰半胱氨酸(N-acetyl cysteine,NAC)和亚硒酸钠(Na2SeO3)对亚慢性染镉大鼠肝肾毒性的影响及其机制。方法32只Wistart大鼠随机分为4组,每组8只,第1组为对照组,第2组为单位染镉组,第3、4组为干预组。大鼠连续6周皮下注射7μmol/kg氯化镉,然后干预组分别腹腔注射1 mmol/kg NAC和10μmol/kg Na2SeO3,共2周;测定大鼠尿N-乙酰-β-苷酶(NAG)、碱性磷酸酶活力(ALP)和肝、肾皮质谷胱甘肽(GSH)、丙二醛(MDA)含量及谷胱甘肽过氧化物酶(GSH-Px)活力。结果亚慢性染镉使大鼠肝、肾皮质和尿镉含量显著升高,尿ALP、NAG和蛋白含量显著升高,肝、肾皮质GSH含量显著升高,GSH-Px活力显著降低。与单纯染镉组比较,NAC处理组尿镉、NAG和蛋白含量显著下降,肝、肾皮质GSH显著降低;Na2SeO3处理组尿镉、ALP及肝、肾皮质GSH含量显著下降,GSH-Px活力显著升高。结论NAC和Na2SeO3对镉致肾损伤的恢复具有促进作用,其机制可能与NAC或Na2SeO3改变体内GSH含量和GSH-Px活力有关。     

北五味子的富硒方法和富硒效应研究

目的探讨在北五味子生长过程中应用亚硒酸钠,是否能有效提高北五味子中硒的含量。方法分别采用土壤施硒、叶面喷硒、土施加叶喷的方法进行试验。结果土壤施硒、叶面喷硒均能使北五味子的硒含量比对照显著提高,并且随着处理浓度的增加而增加。硒含量土施最高可达0.2797mg/kg,叶喷最高可达3.8459mg/kg。结论试验初步验证,硒元素在北五味子中培植转化的富集效应是很明显的。     

The relationship between nutritional antioxidants and serum lipid peroxides in cancer patients

A new parameter, the ratio of lipid peroxide and vitamins E and C [LPO/(VE + VC)], has been proposed and used to reflect the balance between lipid peroxidation and antioxidation capability of cancer patients and of healthy human controls. The effects of vitamins E, C, and selenium on the serum LPO level in mice bearing Ascites Hepatomas (H22) have also been examined. The results showed that the average of LPO/(VE + VC) ratios in cancer patients (135 cases) was significantly higher than that of the normal controls (222 cases). The authors suggest that this ratio might be used as one of the parameters for early diagnosis and prognosis of diseases (including cancers) caused by free radicals and lipid peroxides. The results also showed that antioxidants - Se(Na2SeO3, 1mg/kg) or vitamin E (5mg/kg) could markedly decrease the level of serum LPO in the tumor-bearing animals. A smaller dose of VE (1mg/kg) and doses of Vc up to 300mg/kg showed no effect on the serum LPO levels when given separately. However, synergistic effects were observed when any 2 out of 3 or three nutrients were given together. Those with three nutrients significantly lowered the serum LPO level. These antioxidants also inhibited the proliferation of tumour cells.     

硒驯化平菇对老年期大鼠血脂、血糖的影响

用富硒平菇饲喂衰老 wister大鼠 ,观察血液有关指标。结果显示适当剂量的富硒平菇 ,可以提高谷胱甘肽过氧化物酶活性 ,提高血清清蛋白和高密度脂蛋白的含量 ,降低血清脂质过氧化物、总胆固醇、甘油三脂含量和维持衰老大鼠的正常血糖     

Protective effects of selenium on methimazole-induced anemia and oxidative stress in adult rats and their offspring

The present study investigates the potential ability of selenium, considered as an antioxidant with pharmacological property to alleviate oxidative stress and hematological parameter disorders induced by methimazole, an antithyroid drug. Pregnant Wistar rats were randomly divided into four groups of six each: group I served as negative control and received a standard diet; group II received 250 mg/L of methimazole in drinking water and a standard diet; group III received both methimazole (250 mg/L, orally) and selenium (0.5 mg/kg of diet) supplemented to the standard diet; group IV served as positive control and received a supplement of selenium in the diet (0.5 mg/kg of diet) as sodium selenite (Na(2)SeO(3)). Treatment was started from the 14th day of pregnancy until day 14 after delivery. Methimazole reduced the number of red blood cells, hemoglobin concentration and hematocrit in mothers and their pups. Besides, plasma iron, vitamins B(9), B(12), C and E levels were reduced. Lipid peroxidation increased, objectified by high malondialdehyde levels and lactate dehydrogenase activity in plasma, while glutathione, glutathione peroxidase, superoxide dismutase and catalase activities showed a significant decline. Co-administration of selenium through diet improved all the parameters cited above. It can be concluded that the administration of selenium alleviates methimazole-induced toxicity, thus demonstrating its antioxidant efficacy.     

Excretion and tissue distribution of selenium following treatment of male F344 rats with benzylselenocyanate or sodium selenite.

Benzylselenocyanate (BSC), a synthetic organoselenium compound less toxic than sodium selenite (Na2SeO3), has been demonstrated to inhibit the development of neoplasia in several experimental animal models. We examined the excretion and tissue distribution of total Se after acute administration of BSC compared to Na2SeO3. Male F344 rats were treated po with approximately one-tenth of the LD50 values, our estimate of highest non-toxic dose. The doses administered were 9.85 mg/kg in the case of BSC and 4.35 mg/kg in the case of Na2SeO3. The rats were sacrificed at 1, 6, 24, 72, or 120 hr to obtain biological samples. The levels of total Se were determined by graphite furnace atomic absorption spectrophotometry following microwave digestion. In serum, the highest Se level was observed at 6 hr after administration of either BSC or Na2SeO3: 1.34 +/- 0.07 (mean +/- SE), or 2.09 +/- 0.11 micrograms/ml of serum, respectively. In urine and feces, the cumulative percentages of doses excreted within 3 days of BSC or Na2SeO3 treatment were, respectively, as follows: 11.36 +/- 0.82% and 18.33 +/- 0.77% in urine; and 6.67 +/- 0.66% and 31.14 +/- 4.66% in feces. Among the tissues of BSC-treated rats, the kidneys were found to have the highest Se levels throughout the experimental period (as much as 29 micrograms/g of tissue at 72 hr), followed by liver, small intestine, large intestine, lung, pancreas, heart, and spleen. The results indicate that Se from BSC-treated animals is excreted very slowly and is retained in the organs for a much longer period compared to rats treated with Na2SeO3. Whether the slow excretion and prolonged retention of BSC and/or its metabolites play a role in its chemopreventive action is currently under investigation.     

Dietary selenium and aniline-induced methemoglobinemia in rats

Depletion of selenium from rats for 8 weeks decreased blood glutathione peroxidase activity to 5.7% of that in selenium-supplemented (0.5 ppm selenium as Na2SeO3) rats. Aniline (60 mg/kg, i.p.) resulted in no significant difference in methemoglobin and blood reduced glutathione (GSH) levels between Se-deficient and Se-supplemented rats. A lowered aniline dose (36 mg/kg, i.p.) also resulted in no difference in methemoglobin levels. The selenium-deficient rat was able to reduce methemoglobin induced by aniline as efficiently as the selenium-sufficient rat.     

Diphenyl diselenide and ascorbic acid changes deposition of selenium and ascorbic acid in liver and brain of mice

Sodium selenite (Na2SeO3) is the selenium form used in the composition of dietary supplements, and diphenyl diselenide (PhSe)2 is an important intermediate in organic synthesis, which increases the risk of human exposure to this chemical in the workplace. These compounds have been reported to inhibit the cerebral and hepatic aminolevulinic acid dehydratase (ALA-D) in vitro, and now we show that ascorbic acid can reverse some alterations caused by in vivo selenium exposure, but not ALA-D inhibition. The effect of Na2SeO3 or (PhSe)2 and ascorbic acid on selenium distribution, total non-protein thiol, ascorbic acid content (liver and brain) and haemoglobin was also examined. Mice were exposed to 250 micromol/kg (PhSe)2, or 18.75 micromol/kg Na2SeO3 subcutaneously, and to ascorbic acid, twice a day, 1 mmol/kg intraperitonially, for 10 days. Hepatic ALA-D of mice treated with (PhSe)2 was inhibited about 58% and similar results were observed in the animals that received ascorbic acid supplementation (P<0.01, for (PhSe)2-treated and (PhSe)2+ascorbic acid-treated mice). The haemoglobin content decreased after treatment with (PhSe)2 (P<0.01). However, the haemoglobin content of the (PhSe)2+ascorbic acid group was significantly higher than in the (PhSe)2-treated mice (P<0.05), and similar to control (P>0.10). Ascorbic acid treatment decreased significantly the hepatic and cerebral deposition of Se in (PhSe)2-exposed mice (P<0.01). Hepatic non-protein thiol content was not changed by treatment with (PhSe)2, ascorbic acid or (PhSe)2+ascorbic acid. Hepatic content of ascorbic acid was twice that in mice that received (PhSe)2, independent of ascorbic acid treatment (P<0.001). The results of this study suggest that vitamin C may have a protective role in organodiselenide intoxication.     

The effects of treatment with selenite before and after the administration of [75Se]selenite on the exhalation of [75Se]dimethylselenide

The exhalation of dimethylselenium, as indicated by the respiratory loss of 75Se from injected Na75SeO3, depends not only on the dose, but also on previous exposure. Three days pretreatment with 1.2 mumol/100 g unlabelled selenite increased exhalation of 75Se from 0.1 or 1.2 mumol/100 g Na2 75SeO3 and decreased the retention of 75Se in blood and liver from the higher dose. Similarly the injection of 1.2 mumol/100 g unlabelled selenite 24 h after the last of 3 daily doses of 1.2 mumol/100 g labelled selenite increased the exhalation of 75Se in the following 24 h period. Thus, pre-exposure to selenium increased the exhalation of 75Se by making a higher proportion of the newly injected dose accessible for methylation. The exhaled dimethylselenide, however, is not derived solely from the injected dose, since in pretreated animals, it is possible to demonstrate exchange between injected and deposited selenium.     

Kappa-晒化卡拉胶对实验动物的抗心律失常作用

Kappa-硒化卡拉胶是一含硒有机化合物。ip 9 mg·kg^-1·d^-1×5d或单次ig 35,70,140mg·kg^-1能显著提高乌头碱致大鼠HA的阈剂量,此作用可与Na₂SeO₃ 1 mg·kg^-1·d^-1×5d ip比拟.随着Kappa-硒化卡拉胶ig剂量增加,尚可提高乌头碱所致VE,VT和VF的阈剂量。ip 9mg·kg^-1·d^-1×5 d或ig 70mg·kg^-1能提高BaCl₂致大鼠或哇巴因致豚鼠HA的阈剂量。对BaCl₂致大鼠VF或哇巴因致豚鼠VE的阈剂量,分别在ig70mg·kg^-1与140mg·kg^-1时有提高,而ipNa₂SeO₃ 1 mg·kg^-1·d^-1×5d无此明显影响。