克山病病区粮喂养之大白鼠肝脏甲状腺素5′-脱单碘酶活性的改变

测定了以克山病病区粮和非病区粮喂养之大白鼠肝脏 T_4 5′-脱单碘酶活性和巯基含量。结果表明病区粮组动物肝脏 T_4 5′-脱单碘酶活性下降,其机制可能与低硒和巯基含量不足有关。提出肝脏损伤在克山病发病过程中可能起重要作用,值得深入研究。     

克山病病区粮喂养大鼠心肌细胞膜流动性及膜结合酶活性的研究

本文对比观察了低硒的克山病病区粮和补硒的克山病病区粮喂养大鼠其心肌细胞膜流动性及膜结合酶Na~+—K~+—ATP酶、5′—核苷酸酶活性的变化。实验结果表明,克山病病区粮喂养的大鼠心肌细胞膜流动性及膜结合酶活性均降低;给病区粮补硒0.25ppm后可使上述心肌细胞膜的异常变化得到一定的恢复,据此认为细胞膜流动性异常可能是低硒对膜结合酶影响的中间环节。是低硒导致细胞膜功能障碍的基础。     

钼与硒在缺硒大鼠体内交互作用的研究

本文以克山病病区粮喂养大白鼠造成缺硒动物模型,以病区粮加钼或/和硒作为实验观察,对大鼠全血谷胱甘肽过氧化物酶(GSH-Px),心肌和肝黄嘌呤氧化酶(XOD)活力作了测定。结果表明,病区粮饲料中加入适量硒(0.23ppm)可使全血 GSH-Px 及心肌 XOD 活力显著提高(P<0.01),钼硒合用作用更强。对于肝 XOD,只有钼硒合用时,其活力才显著增高(P<0.01)。饲料中单独加钼(2.0ppm,40ppm)对各酶活力均无明显影响。据此认为,低硒状态不仅使 GSH-Px 活力降低,而且也对钼的生物学活性产生影响。     

补充硒、钼对克山病病区粮所致大白鼠心肌细胞膜通透性改变的影响——用辣根过氧化物酶(HRP)作示踪物的研究

已有研究证实,口服亚硒酸钠能有效地预防克山病急性发病;用施钼肥的方法也可明显降低克山病病区人群发病率。但是有关硒和钼预防克山病发病的机制目前还不十分清楚。我们以前的研究证明,用克山病病区粮喂养的大白鼠心肌细胞膜通透性显著增大,表明病区粮中存在着可致心肌细胞膜损伤的因素。本研究的目的是观察克山病病区粮补充硒或钼对大白鼠心肌细胞膜通透性变化的影响,并藉以了解硒、钼与克山病发病之间的     

亚硝酸钠对心肌谷胱甘肽过氧化物酶的影响及维生素E和硒的保护作用

大白鼠喂饲克山病病区粮,并分别向病区粮加维生素 E 和硒,观察在亚硝酸钠急性中毒情况下各组大鼠心肌谷胱甘肽过氧化物酶的变化。结果表明,亚硝酸钠可使病区粮所饲大鼠心肌谷胱甘肽过氧化物酶活性明显下降,补充维生素 E 或硒则可保护此酶活性防止其下降。提出除低硒外,亚硝酸盐过多及维生素 E 缺乏可能参与了克山病发病环节。     

亚硝酸钠所致大鼠血清甲状腺激素的变化及维生素E和硒对其影响

给大白鼠喂饲克山病病区粮,并分别向病区粮加维生素 E 和硒,观察亚硝酸钠急性中毒情况下各组大鼠血清甲状腺激素的变化。结果表明,亚硝酸钠可干扰甲状腺正常功能,维生素 E 和硒可不同程度地减轻亚硝酸钠的这种毒性作用。提出除低硒外,亚硝酸盐过多及维生素 E 缺乏在克山病发病中可能有重要作用,需要重视。     

硒和钼对缺氧性心肌损伤保护作用的研究

本实验测定了用克山病病区粮喂养的大白鼠在投给亚硝酸钠后,其红细胞和心肌SOD活性、心肌MDA含量以及心肌CPK和LDH的活性,并观察了硒和钼的影响。结果表明,病区粮组动物红细胞SOD活性明显高于病区粮加硒、加钼和加硒加钼以及非病区粮组。在病区粮中加硒可使心肌MDA含量下降,而加钼则对MDA影响不大,但可减少CPK和LDH由心肌细胞的漏出,这表明硒和钼都有减轻心肌损伤的作用。讨论了硒和钼的作用机制并提出硒和钼对于克山病的预防作用是通过不同途径实现的。     

克山病病区粮喂养大白鼠的免疫学实验研究和克山病患者的免疫状态初步探讨

本文报道了克山病病人的免疫功能变化及用克山病病区粮喂养大白鼠的免疫功能改变,研究结果表明,克山病病区人群的免疫功能一般偏低,慢性和潜在型克山病患者免疫球蛋白水平增高,尤以IgA和IgM为显著。克山病患者的抗核抗体阳性率增高,循环免疫复合物水平也有增高的趋势,患者心肌组织中有IgG的沉积,表明克山病患者有免疫学改变,并具有自身免疫反应特点;用克山病病区粮喂养大白鼠,可使其免疫功能受到一定影响,主要表现为T细胞数的减少及T细胞功能的降低,病区粮加硒后对其影响不明显,提示病区粮因素所致的机体免疫功能改变在克山病的发病过程中可能有一定影响,而硒可能只是免疫学改变的一个因素而已。     

克山病区粮养动物心肌T_45~′—脱单碘酶活力的改变及硒和维生素E对其保护作用的研究

本文测定了饲克山病区粮大鼠心肌T_45′—脱单碘酶活性,结果表明病区粮组动物心肌脱碘酶活力明显低于非病区粮组,并在补硒或维生素E后升高。提示心肌组织脱碘酶的损伤所致心肌组织甲状腺激素代谢改变在克山病心肌病变中可能起着重要的作用。     

硒锰对实验大鼠体内GSH—Px,SOD,SDH活性影响

观察在病区粮基础上补硒、锰对大鼠全血谷胱甘肽过氧化物酶（ＧＳＨ—ＰＸ）、心肌琥珀酸脱氢酶（ＳＤＨ）、以及心肌、肝脏超氧化物歧化酶（ＳＯＤ）活性的影响。结果表明：病区粮补硒能提高大鼠全血ＧＳＨ—ＰＸ活性以及心肌ＳＤＨ比活力；病区粮降低ＧＳＨ—Ｐｘ活性以及心肌ＳＤＨ比活力；病区粮加锰使心肌ＳＤＨ比活力更显著地下降；病区粮加硒、锰对大鼠心肌、肝脏组织ＳＯＤ比活力未产生显著性影响。提示低硒高锰饲料可导致心肌组织损伤，硒对心肌有保护作用，并且能提高机体的抗氧化能力。     

Bioavailability to rats of selenium in milk of cows fed sodium selenite or selenited barley

The nutritional availability of Se to rats in two experimental Finnish milks were compared to that in American milk naturally high in Se. The experimental milks had their Se content increased by feeding cows either sodium selenite (selenited milk) or selenited barley (selenited-barley milk). Weanling male rats were fed a low-Se milk powder diet for 4 weeks followed by continued depletion or repletion with graded levels of Se as sodium selenite (standard) or different milks for 4 weeks. Plasma Se level and plasma and liver glutathione peroxidase (GSH-Px) activities were used as criteria of body Se status. The bioavailability of Se was calculated with the slope-ratio method. The Se in the selenited-barley milk was significantly (p less than 0.01) more available than that in the selenited milk when the plasma Se level was the response criterion. On the other hand, the bioavailability of Se from the various milks was not different when plasma or liver GSH-Px activities were used as the response criteria. Overall bioavailability for the selenited milk, selenited-barley milk and American milk was only slightly less than that for the standard (sodium selenite = 1.00), showing that milk is a relatively readily available source of dietary Se.     

亚硒酸钠对糖尿病肾病大鼠肾脏脂联素和nephrin表达的影响

目的 探讨亚硒酸钠对糖尿病肾病大鼠肾脏脂联素和nephrin表达的影响及其相互间的关系,从而研究亚硒酸钠与脂联素、nephrin在糖尿病肾病中的作用机制.方法 通过链脲佐菌素法加高脂饮食诱导模拟大鼠糖尿病肾病模型,实验设完全空白对照组、糖尿病组、糖尿病药物干预组,药物干预组每日给予亚硒酸钠溶液灌胃,其它组给予等量盐水溶液灌胃.10周后处死大鼠,取血、尿标本测相关生化指标,取肾脏组织分别提取DNA和蛋白质标本,石蜡切片光镜观察病理改变及免疫组化分析蛋白表达定位,实时定量PCR法检测脂联素mRNA表达、RT-PCR法检测nephrin mRNA表达,Western印迹法检测脂联素和nephrin蛋白表达.结果 亚硒酸钠干预组大鼠生化指标较糖尿病组明显改善,光镜下观察亚硒酸钠干预组病理改变较糖尿病组明显减轻.免疫组化分析,亚硒酸钠干预组脂联素蛋白着色较糖尿病组明显增强,且肾小管、肾小球内均有着色;糖尿病组nephrin蛋白表达着色较空白对照组减少,亚硒酸钠干预组较糖尿病组着色明显增多.亚硒酸钠干预组脂联素mRNA和蛋白表达明显高于糖尿病组和正常对照组,差异有统计学意义(均P＜0.05).亚硒酸钠干预组nephrin mRNA和蛋白表达均较糖尿病组明显增加,但仍较空白对照组降低,差异均有统计学意义(P＜0.05).结论 亚硒酸钠能促进大鼠肾脏脂联素和nephrin表达,表明亚硒酸钠、脂联素和nephrin在延缓和防治糖尿病肾病的发生发展中可能起重要作用.     

克山病区低硒粮饲养大鼠心肌细胞膜Na~+-K~+ATPase活性的改变

应用酶组织化学、电镜酶细胞化学及酶活性生化定量测定等方法,对用克山病区低硒粮饲养大鼠心肌细胞Na~+-K~+ATPase进行了观察。结果表明,病区粮低硒组动物心肌其酶活性较常规饲料对照组明显减弱,补硒后酶活性有所增加,但尚未恢复至正常对照组水平。     

Effect of ketogenic diet on nucleotide hydrolysis and hepatic enzymes in blood serum of rats in a lithium-pilocarpine-induced status epilepticus

The ketogenic diet (KD) is a high-fat and low-carbohydrate diet, used for treating refractory epilepsy in children. We have previously shown alterations in nucleotidase activities from the central nervous system and blood serum of rats submitted to different models of epilepsy. In this study we investigated the effect of KD on nucleotidase activities in the blood serum, as well if KD has any influence in the activity of liver enzymes such as alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase activities in Wistar rats submitted to the lithium–pilocarpine model of epilepsy. At 21 days of age, rats received an injection of lithium chloride and, 18–19 h later, they received an injection of pilocarpine hydrochloride for status epilepticus induction. The results reported herein show that seizures induced by lithium–pilocarpine elicit a significant increase in ATP hydrolysis and alkaline phosphatase activity, as well as a decrease in ADP hydrolysis and aspartate aminotransferase activity. The KD is a rigorous regimen that can be associated with hepatic damage, as shown herein by the elevated activities of liver enzymes and 5′-nucleotidase in blood serum. Further studies are necessary to investigate the mechanism of inhibition of lithium on nucleotidases in blood serum.     

低硒大鼠microRNA表达谱的变化

目的 探讨低硒大鼠microRNA表达谱的变化。方法 将30只SD大鼠随机分为对照组、低硒组及补硒组,每组各10只,对照组喂养标准饲料,低硒组喂养低硒饲料,补硒组喂养低硒饲料14周后再给予亚硒酸钠补硒3周。各组喂养17周后,检测大鼠的血硒水平。提取各组大鼠心肌组织RNA进行microRNA基因芯片检测,寻找低硒大鼠与正常大鼠microRNA的表达差异。采用GO分析等生物学方法对差异性表达的microRNA基因进行深度的分析,并通过RT-qPCR进行验证。结果 成功构建了SD大鼠低硒模型（血硒含量0 .026 ng/L）,低硒组大鼠血硒水平与对照组相比明显降低(P<0.05),补硒后又明显增加（P<0.05）。通过microRNA基因芯片检测低硒组筛选出显著差异性表达基因共30个,上调基因中表达最显著的为:miR-374,miR-16,miR-199a-5p,miR-195和miR-30e*,下调基因中表达最显著的为:miR-3571,miR-675和miR-450a*。 其中miR-374表达量最高,与低硒密切相关。结论 低硒大鼠中miR-374,miR-16,miR-199a-5p,miR-195,miR-30e*,miR-3571,miR-675,miR-450a*表达显著异常,其中miR-374与低硒关系最为密切。为MicroRNA在克山病的诊断及治疗方面研究提供实验依据。     

克山病病区粮喂饲大鼠维生素E营养状态评价及补充硒和维生素E的影响

克山病病区粮,或在其中补充硒或维生素E(VE)喂饲大鼠21～22周,以非病区粮组大鼠为对照。结果表明:病区粮组大鼠心、肝、脾、肾、骨骼肌、肾上腺和胰腺形态改变不明显;病区粮组大鼠心重:体重比值高于非病区粮组和补充硒或VE组大鼠;病区粮组大鼠24小时尿中肌酸排泄量高于非病区粮组在补充VE组大鼠尿中没有检出肌酸;病区粮组大鼠和非病区粮组大鼠红细胞体外过氧化氢溶血率相同,但都处于高水平,补充硒可明显降低溶血率,补充VE则溶血率更进一步降低。综合上述结果得出结论,病区粮喂养大鼠体内VE储存不能满足其需要。     

Formation of the 37KD Protein-Acetaldehyde Adduct in Liver During Alcohol Treatment is Dependent on Alcohol Dehydrogenase Activity

Protein-acetaldehyde adducts (protein-AAs) are formed in vivo during chronic alcohol ingestion. These protein-AAs reported thus far include a 37KD protein-AA in liver cytosol, cytP450IIE 1-AA in hepatic microsomes, hemoglobin-AA, and serum protein-AAs. It has been postulated that acetaldehyde or perhaps a reactive acetaldehyde radical generated by the microsomal ethanol oxidizing system (MEOS or cytP450IIE1) explains the formation of the cytP450IIE1-AA. The source of acetaldehyde responsible for the formation of the cytosolic 37KD protein-AA has not been determined. In this report, we have examined the effects of pyrazole (an ADH inhibitor) and cyanamide (an aldehyde dehydrogenase inhibitor) on the formation of the 37KD liver protein-AA in vivo and in vitro. It was found that feeding rats with an alcohol-containing liquid diet supplemented with cyanamide enhanced while a diet supplemented with pyrazole completely abolished the formation of the 37KD liver protein-AA. The liver of rats fed the pyrazole supplemented alcohol-containing diet showed significantly higher content of cytP450IIE1 than that of rats fed the diet containing alcohol alone. On the other hand, feeding the cyanamide supplemented alcohol-containing liquid diet did not further enhance the content of cytP450IIE1. Similarly, adding cyanamide to the culture medium enhanced while adding 4-methylpyrazole inhibited the production of the 37KD protein-AA by cultured hepatocytes even though the combination of alcohol and 4-methylpyrazole increased the content of cytP450IIE1 2-fold over that in control cells. These results demonstrate that the formation of the 37KD liver Protein-AA is dependent on ADH and not on MEOS.(ABSTRACT TRUNCATED AT 250 WORDS)     

脱碘酶活性改变在克山病发病机制中的作用

本文测定了饲克山病病区粮大鼠心、肝、肾、甲状腺Ｔ．５＇－脱单碘酶活性。结果表明病区粮组大鼠心、肝、肾组织中的脱碘酶活性明显降低，并在补硒、维生素Ｅ后可使脱碘酶活力恢复正常。提示脱碘酶活性的改变在克山病发病中可能起着重要的作用。     

Alterations in liver nucleic acids and nucleotides in arginine deficient rats

Dietary arginine deficiency is associated with retarded growth and depressed feed intake. Nucleic acid biosynthesis as indicated by the incorporation of [6-¹⁴C]-orotic acid and [³²p]-orthophosphate was significantly depressed in rats fed an arginine deficient diet. The activities of the pyrimidine enzymes, aspartate transcarbamylase (ATC) and dihydroorotate dehydrogenase (DHODH) were significantly increased in rats fed an arginine deficient diet. ATC and DHODH activities in rats fed the arginine deficient diet returned to control activities after 3 wk of feeding. Orotidine 5′ phosphate decarboxylase and orotate phosphoribosyl transferase activities were not affected by dietary arginine availability. In the rat fed an arginine deficient diet there was an increase in total liver pyrimidine nucleotides and a decrease in the total purine nucleotides. Significant alterations in the individual liver nucleotides were also observed. Incubation of various tissues obtained from rats fed an arginine deficient diet or a complete diet with glutamine (5mM) revealed that the liver is the major site of orotic acid synthesis. Orotic acid production in liver slices using glutamine as the nitrogen source was significantly greater in rats fed an arginine deficient diet compared to controls. The orotic aciduria occurring in rats fed an arginine deficient diet is associated with increased synthesis and decreased utilization of pyrimidines.     

克山病区低硒粮饲养大鼠的心肌细胞超微结构及膜通透性改变的实验观察

本实验用克山病区低硒粮喂养大鼠,使动物处于低硒状态,同时增设补硒组和常规饲料组作为对照。饲养二个月后,应用电镜和示踪剂分别观察其心肌细胞超微结构及膜通透性的改变。低硒组大鼠心肌细胞膜不完整,镧颗粒进入细胞内,但线粒体内罕见。质膜经钌红染色呈中等电子密度的不均匀窄带,并经质膜破损处进入心肌细胞内。实验结果表明,低硒可引起大鼠早期心肌细胞超微结构及膜通透性的改变。