亚硒酸钠对人乳腺癌细胞MCF-7的作用研究

[目的]探讨不同浓度亚硒酸钠对人乳腺癌细胞MCF-7的作用.[方法]0、0.5、2、8、32μmol/LNa2SeO3处理人乳腺癌细胞24h后,用MTT比色法检测不同浓度亚硒酸钠对人乳腺癌细胞MCF-7的作用;DNA Ladder抽提试剂盒提取DNA后凝胶电泳法观察亚硒酸钠诱导人乳腺癌细胞凋亡的作用.[结果]随着亚硒酸钠浓度的增加,其对人乳腺癌细胞增殖的抑制作用增强.不同浓度的亚硒酸钠作用MCF-7人乳腺癌细胞24h后,各组均未出现典型的DNA梯状条带.[结论]亚硒酸钠对人乳腺癌细胞增殖具有抑制作用;尚未发现其诱导凋亡的作用.     

亚硒酸钠和维生素C的协同抗突变作用

目的观察亚硒酸钠和维生素C在拮抗烹饪油烟凝集物(COF)的致突变作用方面的表现. 方法在人外周血淋巴细胞培养物中注入一定剂量的亚硒酸钠或一定剂量的维生素C来观察淋巴细胞的姐妹染色单体交换率(SCE率).结果亚硒酸钠可显著降低COF处理过的淋巴细胞SCE率;终浓度0.9×10-7mol/L的亚硒酸钠和90.9ug/ml的维生素C在降低COF处理过的淋巴细胞SCE率方面存在着极显著的协同效应.结论一定剂量的亚硒酸钠和维生素C在拮抗COF的致突变性过程中存在着极显著的协同效应;亚硒酸钠单因素亦存在一定的拮抗作用.     

硒和锌对小鼠成釉细胞DNA损伤的作用研究

目的 探讨硒和锌对小鼠成釉细胞DNA损伤的保护作用.方法 以2.50、5.00、10.00 μmol/L亚硒酸钠用于小鼠成釉细胞为硒作用组,以5.00、10.00、20.00 μmol/L硫酸锌作用于小鼠成釉细胞为锌作用组.细胞作用24h后,采用单细胞凝胶电泳技术(SCGE)检测DNA单链断裂情况.结果 与对照组比较,2.50和5.00 μmol/L亚硒酸钠作用组小鼠成釉细胞DNA损伤的指标尾长、Olive尾矩、尾DNA％和尾长/头长值均明显下降(P＜0.05);10.00 μmol/L亚硒酸钠作用组小鼠成釉细胞的尾长、尾/头长比值较对照组均显著性降低(P＜0.05).与对照组比较,5.00、10.00和20.00 μmol/L硫酸锌作用组可使小鼠成釉细胞尾长和Olive尾距明显下降,差异均有统计学意义(P ＜0.05);5.00和10.00 μmol/L硫酸锌作用组尾长/头长值明显下降(P＜0.05).以Olive尾矩为观察指标,2.50和5.00 μmol/L亚硒酸钠的保护作用要优于10.00μmo1/L亚硒酸钠,以2.50 μmol/L亚硒酸钠保护作用相对较好;10.00和20.00 μmol/L硫酸锌的保护作用要优于5.00μmol/L硫酸锌,以10.00 μmol/L硫酸锌保护作用相对较好.结论 2.50～10.0 μmol/L的亚硒酸钠和5.00～20.00 μmol/L硫酸锌均对成釉细胞DNA损伤具有一定的保护作用,其中2.50 μmol/L亚硒酸钠和10.00 μmol/L硫酸锌的相对保护作用较好.     

维生素E和亚硒酸钠的协同抗突变作用

目的　观察亚硒酸钠和维生素 E对烹饪油烟凝集物 (COF)致突变的拮抗作用。方法　在经过 COF处理的人外周血淋巴细胞培养物中注入一定剂量的亚硒酸钠或一定剂量的维生素 E来观察淋巴细胞的姊妹染色单体交换 (SCE)率。结果　经过 37℃ 4 h温育的亚硒酸钠可显著降低 COF处理过的淋巴细胞 SCE率 ;终浓度分别为 0 .9× 10 - 7mol/ L的亚硒酸钠和 5 μl维生素 E在降低 COF处理过的淋巴细胞 SCE率方面存在着极显著的协同效应。结论　经过 4 h温育的一定剂量的亚硒酸钠和维生素 E在拮抗 COF的致突变性过程中存在着极显著的协同效应 ;亚硒酸钠单因素亦存在一定的拮抗作用     

硒代蛋氨酸与亚硒酸钠对LLC-PK_1细胞DNA合成影响的比较

采用~3H-TdR掺入实验观察了D,L-硒代蛋氨酸与亚硒酸钠对猪肾近曲小管上皮细胞(LLC-PK_1)DNA合成代谢的影响。结果显示,两种硒化合物对DNA的合成均呈双相效应,在硒浓度为0.5～50μmol/L时,能促进DNA的合成,并且D,L-硒代蛋氨酸的作用比亚硒酸钠更为有效;随硒浓度的增高,两种硒化合物均呈现对LLC-PK_1细胞DNA合成的抑制作用,亚硒酸钠的毒性作用明显大于D,L-硒代蛋氨酸,亚硒酸钠浓度为400μmol/L时,LLC-PK_1细胞DNA合成的抑制率为94.1%,而D,L-硒代蛋氨酸浓度为400μmol/L时,仅呈现对LLC-PK_1细胞DNA合成的轻度抑制作用,与文献结果比较,LLC-PK_1细胞对硒的毒性作用有较高的耐受性。     

硒和砷对HepG2细胞氧化应激和DNA氧化损伤及修复的作用

目的研究硒和砷单独及联合作用对HepG2细胞氧化应激和DNA氧化损伤及修复的影响。方法采用不同浓度的硒(2.5、5.0和10.0μmol/L亚硒酸钠)和砷(1.56、3.13、6.25、12.5和25.0μmol/L亚砷酸)为受试物单独或联合处理HepG2细胞。荧光法测定丙二醛(MDA)作为氧化应激的指标,高效液相色谱-电化学检测法(HPLC-EC)测定8-羟基鸟苷(8-OHdG)作为DNA氧化损伤的指标,Western Blot检测hOGG1表达作为DNA氧化损伤修复的指标。结果在硒和砷单独作用的条件下,可观察到:(1)5.0、10.0μmol/L的亚硒酸钠和6.25、12.5、25.0μmol/L的亚砷酸均引起HepG2细胞MDA含量增加、8-OHdG生成增多、hOGG1表达明显下降(P<0.05,P<0.01);(2)较低浓度的亚硒酸钠(2.5μmol/L)具有有限的抑制8-OHdG生成的作用(P>0.05)。在硒和砷联合作用的条件下,可观察到:(1)2.5μmol/L的亚硒酸钠和6.25μmol/L的亚砷酸同时染毒使MDA含量和8-OHdG的生成均较相应砷剂量组下降(P<0.05);(2)2.5μmol/L的亚硒酸钠与6.25、12.5和25.0μmol/L的亚砷酸同时染毒,hOGG1表达与相应砷剂量组比较没有明显差异(P>0.05)。结论5.0、10.0μmol/L的亚硒酸钠和6.25、12.5、25.0μmol/L的亚砷酸均可引起HepG2细胞氧化应激增强、8-OHdG生成增多、hOGG1表达明显下降;一定剂量的硒(2.5μmol/L的亚硒酸钠)对砷诱导的HepG2细胞氧化应激和DNA氧化损伤具有抑制作用,但对砷所致的DNA氧化损伤修复不产生明显影响。     

锌和硒联合作用对二氧化硅处理的细胞生化指标的影响

目的观察葡萄糖酸锌、亚硒酸钠对二氧化硅致肺泡巨噬细胞一氧化氮(NO)含量、一氧化氮合酶(NOS)水平变化的影响及联合作用,寻找两者的最佳剂量组合.方法采用肺灌洗法获得肺泡巨噬细胞(1×109/L)后用二氧化硅染毒,观察组同时加入不同浓度的葡萄糖酸锌、亚硒酸钠以及葡萄糖酸锌 亚硒酸钠溶液,共同培养18 h后检测巨噬细胞中 NO、NOS活力.结果与二氧化硅组比,葡萄糖酸锌、亚硒酸钠可以显著降低NO水平及NOS的活力(P<0.05 );1.5 mg/L的葡萄糖酸锌与1.0 μmol/L 的亚硒酸钠联合作用效果最好.结论本实验证实葡萄糖酸锌、亚硒酸钠单独和联合作用在体外可有效降低二氧化硅粉尘致肺泡巨噬细胞的NO、NOS水平.     

亚硒酸钠对胃癌SGC-7901细胞增殖、凋亡及hTERT表达的影响

目的探讨亚硒酸钠对人胃癌SGC-7901细胞株生长、凋亡和hTERT表达的作用及相关机制。方法用含不同浓度亚硒酸钠(0、0.5、2.5、5.0、8.0μmol/L)的培养液培养SGC-7901细胞24、48、72、96h,用相差显微镜观察亚硒酸钠对SGC-7901细胞形态的影响;MTT法检测亚硒酸钠对SGC-7901细胞增殖的影响;AnnexinV-FITC/PI双染法检测亚硒酸钠对SGC-7901细胞细胞的凋亡的影响;链霉亲和素-生物素-酶复合物(SABC)免疫细胞化学法检测亚硒酸钠对SGC-7901细胞hTERT蛋白表达的影响。结果 (1)MTT法结果显示:用亚硒酸钠培养SGC-7901细胞株24,48,72,96h后,随浓度增加,吸光度值逐渐降低,24h后当亚硒酸钠浓度大于2.5μmol/L时,与对照组比较其吸光度值均明显降低(P<0.01),48、96h后各浓度亚硒酸钠组与正常对照组比其吸光度值均明显降低(P<0.01)。随浓度的增加,亚硒酸钠对SGC-7901细胞生长抑制率逐渐增加。(2)流式细胞仪检测结果显示:亚硒酸钠可促进SGC-7901细胞发生细胞凋亡。5.0、8.0μmol/L亚硒酸钠组比正常对照组凋亡率明显升高(P<0.01)。(3)免疫细胞化学法检测结果显示:亚硒酸钠可降低SGC-7901细胞中hTERT蛋白免疫细胞化学染色的平均光密度(MOD),24h时5、8μmol/L亚硒酸钠组与对照组比MOD明显降低(P<0.01),48h时0.5、5.0、8.0μmol/L亚硒酸钠组与对照组比MOD明显降低(P<0.01),72h时2.5、5.0、8.0μmol/L亚硒酸钠组与对照组比MOD明显降低(P<0.01),96h时实验组与对照组比较MOD均明显降低(P<0.01)。结论亚硒酸钠能抑制SGC-7901细胞生长,诱导其凋亡,其作用机制可能与下调hTERT表达有关。     

亚硒酸钠抑制人胃癌BGC823细胞的作用及其机制探讨

目的观察亚硒酸钠对体外培养的人胃癌BGC823细胞增殖的抑制作用及其作用机制。方法用不同浓度(0、4.0、8.0、10.0μmol/L)的亚硒酸钠处理BGC823细胞24h后,采用四甲基偶氮噻唑蓝比色法(MTT法)检测亚硒酸钠对细胞的增殖抑制作用,流式细胞仪PI染色检测细胞周期,AnnexinV/PI双染法定量检测BGC823细胞凋亡率,FAS蛋白染色流式细胞仪定量检测各实验组细胞间FAS蛋白表达,荧光显微镜观察DAPI染色细胞形态。结果亚硒酸钠可明显抑制BGC823胃癌细胞的增殖,呈剂量依赖性;亚硒酸钠可阻滞细胞于S期和增加BGC823胃癌细胞凋亡率并随剂量增大作用增强;DAPI染色观察到亚硒酸钠给药组出现细胞核浓缩、边缘化以及凋亡小体等细胞凋亡的形态特征;亚硒酸钠可呈剂量依赖地增强FAS蛋白表达。结论亚硒酸钠可显著抑制人BGC823胃癌细胞的增殖,使细胞阻滞于S期,并可诱导细胞凋亡,其机制可能与上调FAS蛋白有关。     

亚硒酸钠对神经皮质细胞氧化损伤作用

目的研究不同剂量亚硒酸钠对小鼠大脑皮层神经皮质细胞的损伤作用。方法选用24h龄ICR小鼠，培养大脑神经皮质细胞，48h后加入不同浓度的亚硒酸钠（0．004，0．020，0．100，0．500μmol／L），四甲基偶氮噻唑蓝试验检测细胞活性、激光共聚焦显微镜检测线粒体膜电位，慧星试验检测细胞DNA损伤。结果高剂量亚硒酸钠（0．1和0．5umol／L）明显抑制皮质神经细胞生长、降低线粒体膜电位、并严重损伤DNA，且呈现剂量效应关系（P〈0．05）。与对照组比较，低剂量亚硒酸钠（0．004和0．020μmol／L）虽然呈现一定毒性作用，但差异无统计学意义（P〉0．05）。结论高浓度亚硒酸钠可引起细胞损伤，降低细胞活力，其机制可能与细胞线粒体结构和功能改变以及DNA结构榻伤有关．     

牛磺酸对低水平铅暴露大鼠神经行为与功能的影响

目的　探讨牛磺酸对低水平铅暴露大鼠神经行为与功能的影响。方法　将成年Wistar大鼠随机分为对照 (Cont)组、铅 (Lead)对照组、Lead+0 .5 %牛磺酸 (Tau)组、Lead+1 .0 %Tau组和 Lead+1 .5 % Tau组 ,自孕 9d起 ,各 Tau补充组母鼠饲料中添加不同水平牛磺酸 ,于孕1 6 d至产后 2 5 d,染铅各组饮 0 .1 4%的醋酸铅蒸馏水。仔鼠于生后 2 5 d与母鼠分笼喂养 ,饮食同母鼠。自生后开始观察生长发育及行为发育情况 ,3 0 d开始做辨别学习能力试验。试验结束后 ,处死动物 ,测血铅 ,脑铅 ,单胺类神经递质 ,乙酰胆碱。结果　 1 .各 Tau补充组脑铅含量 (ng/g)低于Lead组 ,高于 Cont组 (P<0 .0 0 1 )。 2 .负向趋地、听觉惊愕、触须定位达标时间 (d)各 Tau补充组短于 Lead组 (P<0 .0 1 ) ,3 .辨别学习能力试验 ,达到学会标准所用时间 (d) ,各 Tau补充组短于 Lead组 (P<0 .0 0 1 )。4.各脑区去甲肾上腺素含量 Lead+1 .0 % Tau组高于 Lead组而与 Cont组无差别 ,各脑区多巴胺含量 Lead组低于 cont组 ,其中小脑、皮层含量低于 Lead+1 .0 % Tau组 (P<0 .0 5或0 .0 1 )。结论　补充适量牛磺酸对低剂量铅暴露大鼠神经系统发育具有保护作用。     

Effects of taurine on plasma and liver lipids, erythrocyte ouabain sensitive Na efflux and platelet aggregation in Sprague Dawley rats

The effects of taurine on plasma and liver cholesterol, erythrocyte ouabain sensitive Na efflux and platelet aggregation were examined in Sprague Dawley rats fed control or 0.5% cholesterol with 0.2% cholate diet. Plasma and liver levels of total cholesterol were increased significantly (p<0.05) in rats fed cholesterol diet compared to the control, and taurine significantly decreased the elevated plasma level of cholesterol in rats fed cholesterol diet (p<0.05). HDL-cholesterol was decreased in groups fed the cholesterol diet regardless of taurine supplementation and the difference between groups with and without cholesterol was significant (p<0.01). Plasma triglyceride was decreased and liver triglyceride was increased both significantly (p<0.05) in rats fed cholesterol compared to the control. Plasma and liver triglyceride in rats fed taurine was decreased significantly compared to the control (p<0.05). Intracellular Na tended to be lower in rats fed cholesterol or taurine and higher in rats fed cholesterol plus taurine compared to the control. Na efflux through Na-K ATPase and the passive leak of Na was somewhat reduced in rats fed cholesterol or taurine and was augmented in rats fed cholesterol plus taurine compared to the control, which showed a similar trend to the intracellular Na. Taurine supplementation caused a suppression of Na efflux in groups fed control diet and restored the suppressed Na efflux in groups fed cholesterol. Platelet aggregation was significantly decreased in the group fed taurine compared to the control (p<0.05) and the group fed cholesterol plus taurine was also a little lower in aggregation than the group fed cholesterol. Microscopic examination showed that taurine prevented fatty liver in rats fed cholesterol diet. Taurine known for stimulating Na-K ATPase in some cell types rather decreased erythrocyte ouabain sensitive Na-K ATPase in the present study. Taurine had hypolipidemic and hypocholesterolemic effects and inhibited platelet aggregation which may be favorable for prevention of cardiovascular diseases.     

Taurine prevents hypercholesterolemia in ovariectomized rats fed corn oil but not in those fed coconut oil

We studied whether the type of dietary fatty acid influences the preventive effect of taurine on the ovarian hormone deficiency-induced increase in plasma cholesterol concentration in 6-mo-old ovariectomized rats. Rats were fed one of the following four diets for 28 d: purified diets based on corn oil, which is rich in linoleic acid, with or with out taurine (50 g/kg) or purified diets based on coconut oil, which is rich in lauric and myristic acids, with or without taurine. Body mass gain, food intake, liver weight and plasma apolipoprotein (apo) A-I, apo B, LDL and VLDL concentrations were not affected by the diets. On the other hand, taurine lowered the plasma total cholesterol concentration (P < 0.02) in rats fed corn oil, but not in those fed coconut oil. In rats fed both types of oils, taurine increased the LDL receptor mRNA level (P < 0.01), hepatic cholesterol 7alpha-hydroxylase activity (P < 0.01) and fecal bile acid excretion (P < 0.01). Taurine increased the HMG-CoA reductase mRNA level (P < 0.02) in the liver of rats fed coconut oil, but not in those fed corn oil. Taurine increased liver total lipid (P < 0.05) and triglyceride (P < 0.05) concentrations in rats fed corn oil, but not in those fed coconut oil. These results indicate that the effect of taurine on ovarian hormone deficiency-induced changes in cholesterol metabolism is influenced by the type of dietary fatty acids.     

补充牛磺酸对大鼠脂质代谢及神经递质作用的研究

目的研究补充不同水平的牛磺酸对大鼠脂质代谢及神经递质的影响。方法32只断乳雌性别大鼠，经基础饲料适应性饲喂1周后，按体重及血浆总胆固醇水平基本一致的原则分为4组：对照组、低剂量组、中剂量组和高剂量组。对照组为基础饲料组，实验组在基础饲料中分别补充0．6％、1．35％和3．0％的牛磺酸，实验持续5周后处死，检测脂质代谢及神经递质指标。结果补充不同水平的牛磺酸对大鼠脂质代谢指标影响不同，补充0．6％的牛磺酸可明显降低血浆TC、LDL—C，补充3．0％的牛磺酸在降低肝脏TC的基础上升高Apo—AI效果最好；饲料中补充牛磺酸可以提高大鼠脑牛磺酸及蛋白质的积累水平，同时增加NO、AChE的水平，而抑制5—HT和5—HIAA从水平。结论补充不同水平的牛磺酸对大鼠脂质代谢指标的影响不同，牛磺酸可调节大鼠部分神经递质的释放水平。     

The effect of taurine on the cholesterol metabolism in rats fed diets supplemented with cholestyramine or high amounts of bile acid

The effects of taurine on serum cholesterol levels and hepatic cholesterol 7alpha-hydroxylase activity (CYP7A1) were studied in rats fed cholestyramine or high amounts of sodium cholate in order to alter the intestinal pool of bile acids. Rats were fed a diet supplemented with 1% cholesterol and 0.25% sodium cholate (high cholesterol, control; C), and C supplemented with 4% cholestyramine (CH) or 0.75% sodium cholate (BA) for 14 d. Taurine groups were fed the diet supplemented with 3% taurine (CT, CHT and BAT). Compared to rats fed C and BA diets, serum cholesterol levels were significantly reduced in rats fed CT and BAT diets, but a significant reduction of serum cholesterol by taurine feeding was not observed in the CHT group as compared to the CH group. An increase in hepatic CYP7A1 activity due to taurine intake was observed in the CT and BAT groups. However, the simultaneous administration of cholestyramine and taurine (CHT group) did not increase hepatic CYP7A1 activity compared the intake of cholestyramine only (CH group). A significant increase in fecal bile acid excretion due to taurine intake was found only in rats fed the CT diet. In conclusion, it is suggested that taurine facilitates hepatic CYP7A1 activity regardless of the enlarged intestinal pool of bile acids due to increased intake of exogenous bile acid, and then reduces the serum cholesterol concentration.     

The effect of taurine on plasma cholesterol concentration in genetic type 2 diabetic GK rats

The purpose of this study is to investigate the effect of taurine on the plasma cholesterol concentration in genetic type 2 diabetic rats fed cholesterol-free or high-cholesterol diets. Diabetic rats (GK male rats) and normal rats (Wistar male rats) were fed either a cholesterol-free or cholesterol-enriched (1% cholesterol + 0.25% sodium cholate) diet supplemented with or without 3% taurine for 21 or 14 d. Compared to the normal rats, diabetic rats showed a high glucose concentration in their blood and plasma, but it was not affected by taurine feeding. The plasma insulin concentration was higher in the diabetic rats than in the normal rats. At the start of the experiment, the plasma cholesterol concentration was significantly higher in the diabetic rats than in the normal rats. Taurine did not affect the plasma cholesterol level in rats fed the cholesterol-free diet. However, taurine feeding significantly increased the plasma HDL-cholesterol concentration in the diabetic rats fed the cholesterol-free diet. In both the diabetic and normal rats fed the cholesterol diet, the plasma cholesterol concentration was significantly lower in rats fed the diet supplemented with taurine than in the rats fed the control diet. It was concluded that taurine has a hypocholesterolemic effect in both diabetic and normal rats fed diets containing cholesterol. Moreover, these results suggest that taurine seems to affect the HDL-cholesterol metabolism in diabetic rats fed a cholesterol-free diet.     

Effects of dietary taurine supplementation on plasma and liver lipids in OVX rats fed calcium-deficient diet

Taurine supplementation has been shown to have an effect on lowering blood lipids in ovariectomized (OVX) rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on OVX rats fed calcium-deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received a sham operation (Sham). Each rat group was further divided into the control diet and the taurine supplemented (2.0 g/100 g diet) diet group. All rats were fed on calcium-deficient diet and deionized water ad libitum for 6 weeks. Plasma and liver lipids were determined by using commercial kits. LDL-cholesterol concentrations were estimated with the equation of Friedewald et al. (1972). There were no significant differences in body weight gain and food intake between the control and taurine group within Sham and OVX groups, but body weight gain, food intake, and food efficiency ratio was higher in the OVX group. Concentrations of plasma total cholesterol, triglyceride, LDL-cholesterol were significantly lower in the taurine fed group of OVX rats fed Ca deficient diet, while HDL-cholesterol concentration was increased in the taurine fed group. Therefore, in this study, we examined whether taurine also prevented hypercholesterolemia induced by ovarian hormone deficiency in ovariectomized rats when they were fed a calcium-deficient diet. These results indicate that taurine may have some beneficial effects on hypercholesterolemia and hypertriglyceridemia in OVX rats fed calcium-deficient diet.     

母鼠牛磺酸耗竭与补充对仔代脑发育的影响

方法：Ｗｉｓｔａｒ大鼠随机分成三组：１．牛磺酸耗竭组（ＧＥＳ组），母鼠孕１５日至哺乳第１７日向饮水中加入ＧＥＳ（浓度为１％），并给予牛磺酸缺乏膳（饲料牛磺酸含量为０）；２．对照组（Ｃｏｎ组）饲料牛磺酸含量为０．０６％，饮水中不含添加物；３．牛磺酸补充组（ＴＳ组），饲料牛磺酸含量为０．６％，饮水中亦不含添加物。对仔代出生及断乳时的脑重、脑牛磺酸与游离氨基酸含量、脑微量元素Ｚｎ、Ｃｕ、Ｆｅ含量及学习记忆能力进行测定。牛磺酸测定采用离子交换层析法；氨基酸测定采用ＨＰＬＣ法；微量元素Ｚｎ、Ｃｕ、Ｆｅ测定采用原子吸收火焰法；乳鼠学习记忆能力测定采用Ｙ迷宫进行。结果：ＧＥＳ组仔鼠出生及断乳时的脑重、脑牛磺酸与微量元素Ｚｎ含量均低于对照组；在Ｙ迷宫中的学习记忆能力低于母鼠牛磺酸补充组。母鼠牛磺酸补充对仔鼠出生时的脑重、脑牛磺酸含量及与微量元素Ｚｎ含量均无影响；但至断乳时，仔鼠大脑牛磺酸含量、微量元素Ｚｎ、Ｆｅ含量高于正常对照组。     

Dietary taurine alters ascorbic acid metabolism in rats fed diets containing polychlorinated biphenyls

The effect of dietary taurine on ascorbic acid metabolism and hepatic drug-metabolizing enzymes was investigated in rats fed diets containing polychlorinated biphenyls (PCB) to determine whether taurine has an adaptive and protective function in xenobiotic-treated animals. Young male Wistar rats (60 g) were fed diets containing 0 or 0.2 g/kg diet PCB with or without 30 g/kg diet of taurine for 14 d. The rats fed the PCB-containing diets had greater liver weight, higher ascorbic acid concentrations in the liver and spleen and greater hepatic cytochrome P-450 contents than control rats that were not treated with PCB (P < 0.01). In PCB-fed rats, urinary ascorbic acid excretion was enhanced, and serum cholesterol concentration (especially HDL-cholesterol) was significantly elevated compared with those in control rats. Dietary taurine significantly potentiated the increases in the urinary excretion of ascorbic acid and the rise in the levels of cytochrome P-450 which were caused by PCB treatment. On the other hand, the supplementation of taurine to control diet did not alter these variables. Taurine may enhance the hepatic drug-metabolizing systems, leading to the stimulation of the ascorbic acid metabolism in rats fed diets containing PCB.     

Effects of taurine supplementation on bone mineral density in ovariectomized rats fed calcium deficient diet

Taurine supplementation has been shown to have a beneficial effect on femur bone mineral content in ovariectomized rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on ovariectomized rats fed calcium deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received sham operation (SHAM), and received either control diet or a taurine supplemented diet for 6 weeks. All rats were fed on calcium deficient diet (AIN-93: 50% level of calcium) and deionized water. Bone mineral density (BMD) and bone mineral content (BMC) were measured in spine and femur. The serum and urine concentrations of calcium and phosphorus were determined. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. Bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Urinary calcium and phosphorus excretion, osteocalcin in blood and cross link value were not significantly different among the groups. Within the OVX group, the taurine supplemented group had not higher femur bone mineral content than the control group. This study established the need for a study on the taurine effect on bone with different calcium levels.