Infection of young adult mice with dengue virus type 2

Young adult female mice, five to six weeks old, were injected intraperitoneally with 2·5 × 10^6·3 LD₅₀ of dengue-2 virus, New Guinea C strain. The mice were killed on day 1, 2, 3, 4, 5, 6, 7, 10, 14, 21, 28 and 35 respectively. By means of the immunofluorescent antibody technique, viral antigen appeared as irregular granules in the reticuloendothelial cells of liver, lymph nodes and spleen of infected mice on the first day after inoculation and then diminished. From the fifth to sixth day of infection dengue antigen appeared again as homogeneous staining in the cytoplasm of single or groups of mononuclear cells in the lymphatic sinuses only. Later, by the third week of infection, dengue antigen could be seen in the mononuclear cells located in the marginal zone of lymphoid follicle of the spleen, the pattern of staining changing to bright spherical granules. At the same time, the deposition of immune complexes (composed of dengue antigen, mouse gamma and β1C globulin) could be seen in the renal glomeruli of infected mice.Serum antibody to dengue virus was found at low levels, being maximal on the 14th day after infection. Dengue virus was not isolated from the sera or from the infected organs. Granulomatous inflammation developed in lymph nodes and liver of mice infected with dengue virus and in mice inoculated with normal mouse brain suspension. Proliferative glomerular lesion was observed on day 14 after inoculation without definite abnormal urine findings.     

Variations in metallothionein, Zn, Cu, and Fe concentrations and ceruloplasmin activity in pregnant rat dams and their fetuses

Growing rat fetuses have great need for Zn, Cu, and Fe. In fetal livers (FL) large accumulations of Zn and Cu connected with increased metallothionein (MT) synthesis take place. In dams, serum changes in metals concentrations with increased ceruloplasmin (Cp) activity are observed. The aim of this study was to determine (1) mutual relationships in the accumulation of MT, Zn, Cu, and Fe in fetal livers; (2) changes in Zn, Cu, and Fe concentrations in dam serum; and (3) the day with the maximum Cp activity. Sections of rat dams were taken on 16th-21st day of gestation, twice a day, and MT, Zn, Cu, and Fe concentrations in liver, spleen, kidneys, and placenta of dams and in liver and brain in fetuses were determined. In fetal livers high correlations between MT and Zn and between Zn and Cu were obtained. The investigated Cp activity was always high, reaching its maximum on the 20th day and minimum on the 21st day. Significant correlation between Cp activity and Cu concentration in dam serum was also revealed. In conclusion it is suggested that Zn accumulation in FL is strictly connected with MT synthesis but Cu content in FL is rather dependent on Cp activity in dam serum. Iron accumulation in fetal livers is connected with the diminution of iron concentrations in dam serum.     

柯萨奇病毒B3感染大鼠心室肌钙通道基因表达及其功能变化

目的探讨柯萨奇病毒B3(CoxsackieviruB3,CVB3)感染大鼠心室肌钙通道的基因表达特点及其功能改变。方法取1~3日龄新生SD大鼠15只行心室肌细胞原代培养,将培养48 h且已形成规律搏动的心室肌细胞随机分为病毒感染组(CVB3株感染培养,n=8)与正常对照组(n=7),比较两组大鼠的细胞形态、结构变化特点等;采用半定量逆转录聚合酶链反应(RT-PCR)检测两组大鼠L型钙通道亚单位mRNA的表达;应用全细胞膜片钳技术对CVB3感染前后心室肌细胞L型钙电流(ICa-L)变化进行测定,记录细胞膜电容(Cm)、电流密度、电压依赖性激活与失活等动力学参数。结果正常心室肌细胞主要表现为三角形、梭形、多边形等形态,搏动规律有力,搏动细胞百分比>95%;接种CVB3培养3 d后细胞搏动开始减慢且呈不规律搏动,细胞变圆、扁梭,折光性增强,最终停止搏动、脱落、死亡;CVB3感染3 d后,溶酶体增多,线粒体空泡变形,细胞核肿胀,核膜破裂。病毒感染组心室肌细胞L型钙通道α1和β亚单位mRNA表达水平分别为(4.02±0.07)、(2.08±0.06)均高于正常对照组(P<0.05);而两组α2/δ亚单位mRNA表达水平差异无统计学意义。在-20~+10 mV测试电压下,病毒感染组ICa-L密度为(-8.65±0.99),较正常对照组明显增加(P<0.05);但CVB3感染培养对大鼠心室肌细胞Cm、电压依赖性激活与失活特性无显著影响。病毒接种后第4天,病毒感染组CVB3特异蛋白基因片段RNA均为阳性,正常对照组CVB3特异蛋白基因片段RNA均为阴性,差异有统计学意义(P<0.05),病毒感染组病毒接种1~4 d CK-MB浓度均高于正常对照组(P<0.05)。结论 CVB3感染大鼠心室肌细胞L型钙通道α1和β亚单位mRNA表达上调,ICa-L密度增大,可能是CVB3感染对心室肌细胞产生损伤作用的病理机制。     

二氧化硫对小鼠超氧化物歧化酶活性的影响

[目的]观察二氧化硫（SO2）对小鼠9种脏器超氧化物歧化酶（SOD）活性的影响。[方法]采用整体动物吸入染毒方式，测定小鼠吸入SO2气体后不同脏器SOD活性的变化。[结果]小鼠吸入较低浓度的SO2后，SOD活性变化因脏器而异；肝，肾，心，脾，脑，小肠，睾丸组织的SOD活性呈下降趋势，肺和胃组织的SOD活性呈上升趋势，但在较高SO2吸入浓度下，9种脏器SOD活性显著下降。[结论]SO2吸入体内会引起机体上述组织抗氧化能力下降。造成机体的氧化损伤。     

Total Mercury and Methylmercury Residues in River Otters (<Emphasis Type="Italic">Lutra canadensis</Emphasis>) from Wisconsin

The Wisconsin Department of Natural Resources (WDNR) collected trapper-caught river otter (Lutra canadensis) from 3 distinct areas of Wisconsin (north, central, and south). Otter carcasses were collected from a total of 12 counties during the trapping seasons of 2003 and 2004. Liver, kidney, muscle, brain, and fur tissue was collected for mercury (Hg) analysis. Analysis of variance identified collection zone as the significant factor for differences in tissue Hg levels, with a pattern of decreasing Hg concentrations from north to south (p < 0.0001). This trend was apparent in all tissue types analyzed. Strong relationships were observed between Hg concentrations in all tissues. Likewise, highly significant (p < 0.0001) relationships were found to exist between Hg concentrations in otter fur and Hg concentrations of internal organs (brain, muscle, kidney, and liver). Although these data suggest that Hg concentrations are related among tissues, they do not suggest uniform distribution of Hg throughout the tissues. The results suggest that Hg accumulates at higher concentrations in fur followed by liver, kidney, muscle, and brain. Analysis of a subset of samples for methylmercury (MeHg) revealed that MeHg made up a greater percentage of total Hg in brain and muscle compared to liver and kidney tissue. Although a gradient in tissue concentrations was observed from north to south, none of the tissue concentrations reached levels known to cause toxicity in either otter or mink.     

Dietary zinc deficiency and repletion modulate metallothionein immunolocalization and concentration in small intestine and liver of rats

Metallothionein (MT) functions in zinc (Zn) homeostasis and dietary Zn affects tissue MT concentration. The objective of this study was to investigate the effects of dietary Zn deficiency and 24-h Zn repletion on MT immunolocalization and concentration in the small intestine and liver of growing rats. Three-week-old rats fed Zn-deficient diet (< 1 mg Zn/kg) for 16 d had no MT staining in either small intestine or liver. After 24-h Zn repletion with control diet (30 mg Zn/kg), strong MT staining was observed in intestinal Paneth cells and surface epithelial cells in the proliferative regions of villi. Pair-fed control rats had strong MT staining in liver that was localized around central veins. After 24-h energy repletion, the hepatic MT staining diminished. Furthermore, Zn-deficient rats had significantly reduced intestinal (57%) and hepatic (61%) MT concentrations but unaffected Zn concentrations compared with controls that consumed food ad libitum. Zn repletion for 24 h restored intestinal and hepatic MT concentrations and reduced hepatic Zn concentration. Pair-fed control rats had elevated MT concentration in liver that was normalized by energy repletion. There was a significant positive correlation between tissue Zn and MT concentrations in liver (r = 0.60, P = 0.0001), but not in small intestine. In summary, MT immunolocalization and concentration in rat small intestine and liver were responsive to changes in Zn status, supporting the role of MT in Zn metabolism. Cell-type-specific localization of MT in small intestine after dietary Zn manipulations indicates a function of Zn and MT in gut immunity and intestinal mucosal turnover, and the pattern of hepatic MT distribution with energy restriction may be linked to detoxification processes.     

A comparative study of the effect of UV and formalin inactivation on the stability and immunogenicity of a Coxsackievirus B1 vaccine

Type B Coxsackieviruses (CVBs) belong to the enterovirus genus, and they cause both acute and chronic diseases in humans. CVB infections usually lead to flu-like symptoms but can also result in more serious diseases such as myocarditis, aseptic meningitis and life-threatening multi-organ infections in young infants. Thus, CVBs have long been considered as important targets of future vaccines.We have previously observed CVB1 capsid disintegration and virus concentration decrease with 12-day long formalin inactivation protocol. Here a scalable ion exchange chromatography purification method was developed, and purified CVB1 was inactivated with UV-C or formalin. Virus morphology and concentration remained unchanged, when the UV (2 min) or formalin (5 days) inactivation were performed in the presence of tween80 detergent. The concentration of the native and UV inactivated CVB1 remained constant at 4 °C during a six months stability study, whereas the concentration of the formalin inactivated vaccine decreased 29% during this time. UV treatment decreased, whereas formalin treatment increased the thermal stability of the capsid.The formalin inactivated CVB1 vaccine was more immunogenic than the UV inactivated vaccine; the protective neutralizing antibody levels were higher in mice immunized with formalin inactivated vaccine. High levels of CVB1 neutralizing antibodies as well as IgG1 antibodies were detected in mice that were protected against viremia induced by experimental CVB1 infection.In conclusion, this study describes a scalable ion exchange chromatography purification method and optimized 5-day long formalin inactivation method that preserves CVB1 capsid structure and immunogenicity. Formalin treatment stabilizes the virus particle at elevated temperatures, and the formalin inactivated vaccine induces high levels of serum IgG1 antibodies (Th2 type response) and protective levels of neutralizing antibodies. Formalin inactivated CVB vaccines are promising candidates for human clinical trials.     

二氧化硫吸入对小鼠9种脏器GSH和GSH/GSSG的影响

为研究二氧化硫 (SO2 )吸入后小鼠多种脏器内抗氧化物质谷胱甘肽 (GSH)和抗氧化系统GSH GSSG(GSSG为氧化型谷胱甘肽 )的变化 ,采用SO2 动态吸入染毒技术 ,使昆明小鼠吸入不同浓度SO2 后 ,用分光光度法测定不同脏器GSH含量 ,并计算GSH GSSG比值。结果表明 :(1)在SO2 浓度为 2 2mg m3时 ,雌、雄鼠所试脏器GSH水平和GSH GSSG均无显著变化 ;(2 )在SO2 浓度为 64mg m3时 ,雌鼠GSH水平和GSH GSSG变化不大 ,而雄鼠肺、肾、脑、胃、睾丸中GSH水平显著降低 ;(3 )在SO2 浓度为 148mg m3时 ,雌、雄鼠各脏器GSH水平和GSH GSSG均有下降 ,其中GSH在雄鼠肝、肺、肾、心、脑、胃、小肠、睾丸和雌鼠肝、肺、肾、小肠中下降显著 ,GSH GSSG在雄鼠肝、肾、小肠、睾丸和雌鼠肝、肺、肾、脑、胃、小肠中下降显著。以上结果说明一定浓度的SO2 吸入不仅影响小鼠呼吸器官 ,而且对多种脏器都有作用 ,同时显示雌、雄小鼠对SO2 的敏感性不同。GSH含量减少和GSH GSSG下降提示SO2 的毒作用与其降低体内抗氧化物质水平、削弱体内抗氧化防御系统有关     

Gestational mercury vapor exposure and diet contribute to mercury accumulation in neonatal rats

Exposure of pregnant Long-Evans rats to elemental mercury (Hg0) vapor resulted in a significant accumulation of Hg in tissues of neonates. Because elevated Hg in neonatal tissues may adversely affect growth and development, we were interested in how rapidly Hg was eliminated from neonatal tissues. Pregnant rats were exposed to 1, 2, or 4 mg Hg0 vapor/m3 or air (controls) for 2 hr/day from gestation day 6 (GD6) through GD15. Neonatal brain, liver, and kidney were analyzed for total Hg at various times between birth and postnatal day 90 (PND90). Milk was analyzed for Hg between birth and weaning (PND21). Before weaning, the Hg levels in neonatal tissues were proportional to maternal exposure concentrations and were highest in kidney followed by liver and then brain. There was no elimination of Hg between birth and weaning, indicating that neonates were exposed continuously to elevated levels of Hg during postpartum growth and development. Consumption of milk from exposed dams resulted in a slight increase in kidney Hg concentration during this period. Unexpectedly, neonatal Hg accumulation increased rapidly after weaning. Increased Hg was measured in both control and exposed neonates and was attributed to consumption of NIH-07 diet containing trace levels of Hg. By PND90, tissue Hg levels equilibrated at concentrations similar to those in unexposed adult Long-Evans rats fed the same diet. These data indicate that dietary exposure to trace amounts of Hg can result in a significantly greater accumulation of Hg in neonates than gestational exposure to high concentrations of Hg0 vapor.     

温室土壤有机提取物靶器官毒性研究

目的探寻温室土壤中有机提取物（extractable organic matter,EOM）毒性作用的主要靶器官。方法提取某温室土壤中的EOM,将40只昆明雄性小鼠随机分为对照（DMSO）组、EOM低剂量组（0.5 g/mL）、中剂量组（1.5 g/mL）和高剂量组（3.0 g/mL）,每组10只。对小鼠进行EOM灌胃染毒,染毒容量为10 mL/kg,每天1次,连续染毒4周。最后计算小鼠染毒前后体重净增值,心、肝、脾、肺、肾、脑的脏器系数,并检测这些组织和血清中的超氧化物歧化酶（SOD）活力与丙二醛（MDA）含量。结果 EOM对小鼠染毒前后体重净增值和各组织脏器系数未有明显影响。与对照组相比,EOM低剂量组的肝、肾和脾组织SOD活性有所升高,高剂量组显著降低,且EOM各剂量组间肝、肾、脾、脑及血清中MDA含量皆具有统计学差异。结论温室土壤中EOM可诱导肝、肾、脾、脑和血清等靶器官产生脂质过氧化损伤作用。     

浙江省2008年病毒性脑膜脑炎病原柯萨奇B组5型病毒VP_1区基因变异分析

目的研究浙江省2008年病毒性脑膜脑炎中分离到的柯萨奇B组5型病毒(Coxsackie Virus B5,CVB5)VP1区的基因特征,并与其他国家的分离株和CVB5原型株进行比较,探讨病毒VP1区的变异与病毒性脑膜脑炎流行的关系。方法用人喉癌上皮细胞和人横纹肌肉瘤细胞对脑脊液(Cerebrospinal Fluid,CSF)和粪便标本进行病毒分离,对分离到的病毒株提取核糖核酸,再用逆转录-聚合酶链反应扩增CVB5VP1区基因片段并进行序列测定,用DNA MAN和Bioedit等软件进行分析处理。结果从浙江省2008年病毒性脑膜脑炎患者CSF和粪便标本中,分离到的5株CVB5,其VP1区的核苷酸长度均为735bp,未发现核苷酸插入与丢失。与浙江(Zhejiang,ZJ)/12/02株氨基酸同源性最高为99.6%～100%,与法国等国外毒株的同源性为97.3%～99.6%,而与CVB5原型株的同源性只有96.3%。不同年份、不同地点分离的CVB5在进化树上显示在同一个分支上。结论2008年引起浙江省病毒性脑膜脑炎的CVB5的VP1区变异较小,引起的病毒性脑膜脑炎在局部地区散发,未发生明显的流行。     

Absorption and metabolism of pyridoxamine in mice. I. Pyridoxal as the only form of transport in blood.

[3H]Pyridoxamine was orally administered to mice in physiological amounts, and the distribution of isotope between the six recognized forms of vitamin B6 and pyridoxic acid was determined at different times in the intestine, liver, blood, and brain. After 7 min about 50% of the radioactivity in pyridoxamine had been absorbed by the intestine and transported to the blood and other organs. Labeled pyridoxal phosphate was found in the intestine and liver. Labeled pyridoxamine could not be detected in the peripheral blood, but substantial amounts of labeled pyridoxal and pyridoxal phosphate were found in the blood. However, when a large amount (40-140 nmol) was given, a significant amount of labeled pyridoxamine was found in the blood, together with labeled pyridoxal and pyridoxal phosphate. These results suggest that the intestine and/or liver play a major role in completely converting physiological amounts of pyridoxamine to circulating pyridoxal, which is then taken up and phosphorylated by other organs.     

Crosstalk between innate and adaptive immune responses to infectious bronchitis virus after vaccination and challenge of chickens varying in serum mannose-binding lectin concentrations

Mannose-binding lectin (MBL), a C-type collectin with structural similarities to C1q, is an innate pattern-recognition molecule that is sequestered to sites of inflammation and infections. MBL selectively binds distinct chemical patterns, including carbohydrates expressed on all kinds of pathogens. The present study shows that serum MBL levels influence the ability of chickens to clear the respiratory tract of virus genomes after an infectious bronchitis virus (IBV) infection. The primary IBV infection induced changes in circulating T-cell populations and in the specific antibody responses. Serum MBL levels also influenced IBV vaccine-induced changes in circulating T-cell populations. Moreover, addition of mannose to an IBV vaccine altered both vaccine-induced changes in circulating T-cell populations and IBV specific vaccine and infection-induced antibody responses in chickens with high serum MBL levels. These data demonstrate that MBL is involved in the regulation of the adaptive immune response to IBV.     

NO2-/NO3- levels in blood and principal organs in rats treated with lipopolysaccharide

It is well revealed that activation of macrophages stimulated by endotoxin resulted in induction of nitric oxide synthase which catalyze nitric oxide (NO) formation from L-arginine. Consequently, blood concentrations of NO2-/NO3- (NOx-) are shown to increase. We studied on pharmaco/toxicokinetics of NOx- in serum and principal organs in Wistar male rats after i.p. administrations of LPS and NaNO3. The serum levels of NOx- at 1 h and 6 h after nitrate administration (10 mg/kg, i.p.) were 240 and 120 microM, respectively. Tissue levels of NOx- in lung, liver and kidneys were ca.1/2 of the serum level. Those levels in spleen and brain were ca.1/4 and 1/10 of the serum level, respectively. The correlation of NOx- levels in serum and these 5 organ tissues between 1 h and 6 h after administration of nitrate was r = 0.992 suggesting no specific accumulation of NOx- in these organs. The serum level of NOx- at 18 h after LPS treatment (1 mg/kg, i.p.) was 430 microM. The correlation of NOx- levels in serum and 5 organ tissues between LPS and nitrate administrations was shown to be r = 0.851. NOx- levels of serum, lung, kidneys and brain showed good correlation but liver and spleen showed out of the correlation. The liver tissue level of NOx- after LPS treatment was low compared with the expected value from the serum level. The reason may be explained partially by the liver weight increase and the liver toxicity with increased GPT and gamma-GT levels due to LPS. Contrary to this, NOx- level of spleen tissue after LPS treatment was more than 2-fold compared with the expected value from the serum level suggesting NO formation in the spleen. This was supported by the markedly high concentration (73.2 nmol/g tissue) of NO2- in the spleen tissue. NO2- levels in lung (34.5 nmol/g tissue) and brain (14.3) were also found to be significantly high after stimulation with LPS suggesting NO formation in these organs. Increased formation of NO2- in these organs by LPS stimulation suggests the formation of active nitrogen oxides such as N2O3 which is an effective nitrosating agent in non-acidic conditions in vivo.     

柯萨奇B4病毒感染ICR小鼠的实验研究

目的:研究柯萨奇B4病毒(CVB4)jlu06株感染对ICR小鼠的致病性。方法:CVB4jlu06株感染ICR小鼠后,定期称量体重,检查小鼠各组织病毒滴度及病理变化,进行免疫组化分析及糖耐量测定。结果:感染组小鼠体重比对照组低,且差异有显著意义;胰腺组织中病毒滴度比其他组织高,胰腺组织损害严重,其他组织器官未见明显病变;免疫组化染色在胰腺组织中检测到大量病毒抗原;感染组糖耐量水平比对照组明显降低,差异有统计学意义。结论:CVB4jlu06株感染可引起ICR小鼠糖尿病样综合征,其感染可能与Ⅰ型糖尿病的发生密切相关。     

Oxidative stress responses in different organs of Jenynsia multidentata exposed to endosulfan

We evaluate antioxidant responses of Jenynsia multidentata experimentally exposed to sublethal concentrations of endosulfan (EDS). The main goal was to determine differences in the response between different organs to assess which one was more severely affected. Thus, we exposed females of J. multidentata to EDS during 24h, measuring the activity of GST, GR, GPx, CAT and LPO in brain, gills, liver, intestine and muscle of both exposed fish and controls. GST activity was inhibited in gills, liver, intestine and muscle of exposed fish but was induced in brain. GR and GPx activities were increased in brain and gills at 0.014 and 0.288 microg L(-1), respectively. GPx activity was inhibited in liver and muscle at all studied concentrations whereas inhibition was observed in the intestine above 0.288 microg L(-1). Exposure to 1.4 microg L(-1) EDS caused CAT inhibition and increase of LPO levels in liver. LPO was also increased in brain at almost all concentrations tested. We find that the brain was the most sensitive organ to oxidative damage. Thus, J. multidentata could be used as a suitable bioindicator of exposure to EDS measuring activities of antioxidant enzymes in brain and liver as biomarkers.     

Vaccination with coxsackievirus B3 virus-like particles elicits humoral immune response and protects mice against myocarditis

Coxsackievirus B3 (CVB3), along with other enteroviruses, is involved in about 50% of myocarditis cases and in the pathogenesis of dilated cardiomyopathy. Prevention of CVB3 infection is therefore highly desirable. Virus-like particles (VLPs) are structurally similar to native virus particles and therefore are far better immunogens than any other subunit vaccines. Recombinant baculoviruses carrying either the intact, entire coding region of CVB3 or the four individual coding regions for virus proteins 1-4 (VP1-4) were constructed. Expression of CVB3 capsid proteins in insect cells infected with recombinant baculovirus was detected by immunofluorescence and Western blot analysis. Sucrose gradient ultracentrifugation fractions of the infected cell lysates contained peaks of CVB3 antigen with an approximate density of 1.14g/ml. Electron microscopy demonstrated the presence of VLP in these sucrose fractions. The CVB3 VLP was non-infectious in tissue culture. SWR (H-2(q)) mice vaccinated with CVB3 VLP developed antibodies to CVB3 capsid proteins after the first boost. Antibody titre was comparable to the level induced by an attenuated CVB3 vaccine. Vaccinated animals were protected from myocarditis when subsequently challenged with cardiovirulent CVB3 (chimera-2). Vaccination with VLP produced from the complete CVB3 coding region gave a greater immune response and afforded better protection than with VLP from the quadruple expression vector. These results demonstrate that CVB3 capsid proteins expressed in insect cells have the intrinsic capacity to assemble into non-infectious VLP, which afforded protection from CVB3 infection to mice when used as a vaccine.     

Effect of cadmium on prenatal development and on tissue cadmium, copper, and zinc concentrations in rats

Administration of 60 and 180 ppm Cd in the drinking water of female rats from Day 1 to Day 20 of gestation resulted in a pronounced accumulation of Cd in all organs examined with the highest increase in the intestinal wall. The copper concentration was decreased in the liver and in the intestine of females from both groups in a dose-dependent manner and in the blood of females given Cd (180 ppm). The zinc concentration was decreased only in the kidney and the intestine of females from the higher level group. The serum glucose level, hemoglobin, and hematocrit were not affected in maternal blood, but the hematocrit was reduced in fetal blood in the 60-ppm Cd group. The fetal body weight and length were decreased in both groups though litter size was not affected. The fetal growth retardation was not concomitant with an increase of Cd concentration or with a decrease of copper and zinc concentration in fetal organs. Cd concentration was not changed in the fetal brain, liver, and kidney and increased only in the gastrointestinal tract of fetuses from the 180-ppm Cd group. The zinc concentration was decreased in fetal liver in the 180-ppm group and in brain of fetuses from the 60-ppm Cd group. The copper concentration was decreased in the gastrointestinal tract and increased in kidney of fetuses from the higher level group. The decrease of copper and zinc concentrations in maternal organs is discussed in terms of the transfer of trace metals to the fetus and their reduced absorption in the intestine.     

金属硫蛋白对铬染毒小鼠肝脏氧化损伤的修复作用

目的：探讨金属硫蛋白（MT）对六价铬（Cr6^＋）染毒小鼠肝脏氧化损伤的修复作用。方法：60只清洁级昆明（KM）种小鼠雌雄各半,随机分为5组：对照组,铬（Cr6^＋）染毒组（50mg／kg）,低、中、高（5．0、10．0、20．0mg／kg）剂量MT保护组。对照组灌胃生理盐水,铬染毒组按50nag／（kg·bw）灌胃重铬酸钾溶液;MT保护组在给予铬染毒的同时继续分别按5．0、10．0、20．0mg／（kg·bw）剂量灌胃MT。各组灌胃时间均为15d,每日1次;灌胃体积均为0．1ml／（10g·bw）。实验结束麻醉处死动物采血,取肝脏计算其脏器系数;全自动生化分析仪检测肝功能AST、ALT、GGT含量;试剂盒检测肝组织SOD活性和MDA含量。结果：与对照组比较,铬染毒小鼠体重降低、肝脏器系数增高、血清AST、ALT、GGT增高、SOD活力下降、MDA含量增高（P〈0．05）。经MT保护后与铬染毒组比较小鼠体重有所回升、肝脏脏器系数下降、血清AST、ALT、GGT降低、SoD活力升高、MDA含量下降,其恢复程度与MT呈剂量－效应关系（P〈0．05）。结论：铬（Cr6^＋）对小鼠肝脏有损伤作用,MT对肝脏有保护作用,其机制与抗氧化作用有关。