甘草甜素和齐墩果酸对大鼠镉中毒性肝损伤的防护作用与机理

为探讨甘草甜素（ＧＬ）和齐墩果酸（ＯＡ）对大鼠镉中毒性肝损伤的防护作用及其作用机理,给大鼠腹腔注射ＣｄＣｌ２溶液（０．８ｍｇＣｄ＾２＋／ｋｇ体重）,两组染镉大鼠分别同时皮下注射ＧＬ的生理盐水溶液（２０ｍｇ／ｋｇ,每周３次）和ＯＡ的吐温－生理盐水混悬液（６０ｍｇ／ｋｇ,每周５次）,测定血清转氨酶、肝镉（Ｃｄ）、金属硫蛋白（ＭＴ）含量,检查肝组织病理形态学。结果显示：ＧＬ和ＯＡ延缓、降低了镉引起的血清     

The effects of zinc deficiency on turnover of cadmium-metallothionein in rat liver

The object of this experiment was to determine the effects of Zn deficiency on the turnover of Cd-induced metallothionein (MT) in rat liver. Male rats were fed a purified Zn-deficient or Zn-adequate diet. After 13 days, the rats were given three daily injections of Cd2+ totaling 1.5 or 3.0 (Zn-deficient) and 3.0 or 6.0 (Zn-adequate) mg Cd/kg body weight. The MT was labeled by injecting the rats with [35S]cystine 2 hours after the final Cd injection. One, 3 or 5 days after labeling, the rats were killed, and their livers were assayed for MT 35S and metal content. The metal composition of MT (mole %) was 41-42% Cd, 51-54% Zn and 4-7% Cu in the Zn-adequate groups and 64% Cd, 27-31% Zn and 6-9% Cu in the Zn-deficient groups. The half-lives of Cd-induced MT in the Zn-deficient rats were 2.6 days (1.5 mg Cd/kg) and 2.8 days (3.0 mg Cd/kg). In the Zn-adequate rats, the half-lives were 3.6 days (3.0 mg Cd/kg) and 3.1 days (6.0 mg Cd/kg). The half-lives of general, soluble hepatic proteins were 4.1 to 4.3 days in all groups. Despite the stabilizing effect of the higher Cd content, the half-life of hepatic MT in the Zn-deficient rats was significantly shorter than in the Zn-adequate rats. These results indicate that hepatic MT degradation is faster in Zn-deficient animals.     

亚硒酸钠与核黄素联合暴露对高脂饮食大鼠血脂及血清肝生化指标的影响

目的研究亚硒酸钠与核黄素联合暴露对高脂饮食雄性大鼠血脂及血清肝生化指标的影响。方法将60只健康SPF级雄性SD大鼠按体重随机分为空白对照组(10只)和高脂组(50只),分别给予基础饲料和高脂饲料;喂养4周后,将50只高脂组大鼠按照血脂水平和体重随机分为5组,分别为高脂对照组、1.84μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组、18.40μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组、1.84μg/kg亚硒酸钠+3.50 mg/kg核黄素干预组和18.40μg/kg亚硒酸钠+3.50 mg/kg核黄素干预组,每组10只。采用灌胃方式进行染毒,同时,空白对照组和高脂对照组给予相同体积的生理盐水,染毒容量为10 ml/kg,每天1次,连续60 d。分别于第0(染毒前)、20、40、60天,测定大鼠血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)水平;并于第60天,检测大鼠血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转氨酶(AST)的水平。结果与空白对照组比较,染毒期间高脂对照组及各干预组大鼠血清TC、TG、LDL-C的水平均升高,除第60天时1.84μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组大鼠血清TG水平外,差异有统计学意义(P0.05);而血清HDL-C水平均未见显著变化。与高脂对照组相比,第20、40天时1.84μg/kg亚硒酸钠+0.70mg/kg核黄素干预组大鼠血清TC、TG的水平及1.84μg/kg亚硒酸钠+3.50 mg/kg核黄素干预组大鼠血清TG的水平以及第60天时1.84μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组大鼠血清TC、TG、LDL-C的水平及18.40μg/kg亚硒酸钠+0.70mg/kg核黄素干预组大鼠血清TC的水平均下降,差异有统计学意义(P0.05);而各干预组大鼠血清HDL的水平均无明显改变。与空白对照组比较,高脂对照组、18.40μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组和1.84μg/kg亚硒酸钠+3.50mg/kg核黄素干预组大鼠血清ALT的水平以及高脂对照组、18.40μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组和18.40μg/kg亚硒酸钠+3.50 mg/kg核黄素干预组大鼠血清AST的水平均升高,差异有统计学意义(P0.05)。与高脂对照组相比,仅1.84μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组大鼠血清ALT的水平降低,差异有统计学意义(P0.05);1.84μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组、18.40μg/kg亚硒酸钠+0.70 mg/kg核黄素干预组以及1.84μg/kg亚硒酸钠+3.50 mg/kg核黄素干预组大鼠血清AST的水平降低,差异均有统计学意义(P0.05)。结论适量亚硒酸钠与核黄素联合暴露可以拮抗高脂饮食所致雄性大鼠血脂及血清肝生化指标的升高。     

高硒高镉致大鼠组织脂质过氧化作用与中毒损伤关系的研究

给成年雄性Wistar大鼠分别和同时腹腔注射Na_2SeO_3(3mg/kg)、CdCl_2(1mg/kg),对照组大鼠腹腔注射等量生理盐水各3天,研究高硒高镉致大鼠组织脂质过氧化作用与中毒损伤的关系,结果表明,给大鼠同时注射Se和Cd显著地拮抗Se致肝脏GSH水平下降和LPO含量增加以及Cd致肾脏、睾丸GSH水平下降和LPO含量增加,但同时给大鼠注射Se和Cd对单独Cd注射致肝、肾SOD活性增加没有明显影响,病理组织学检查发现,给大鼠同时注射Se和Cd显著拮抗Se致肝脏、Cd致肾脏、睾丸的严重损伤。     

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。     

Antioxidant effect of Hemidesmus indicus on ethanol-induced hepatotoxicity in rats

The antioxidant effect of the ethanolic root extract of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant used in soft drinks in India, was studied in rats with ethanol-induced hepatotoxicity. Administering 20% ethanol (5 g/kg of body weight/day) for 60 days to male Wistar rats resulted in significantly decreased body weight and increased liver/body weight ratio. The liver marker enzymes, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatae (ALP), gamma-glutamyl transpeptidase (GGT), and lactate dehydrogenase (LDH), were elevated. In addition, the levels of plasma, erythrocyte, and hepatic thiobarbituric acid-reactive substances (TBARS), hydroperoxides (LOOH), and conjugated dienes (CD) were also elevated in ethanol-fed rats as compared to those of the experimental control rats. Decreased activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), vitamin C, and alpha-tocopherol (vitamin E) were also observed in ethanol-administered as compared to control rats. Ethanolic root extract of H. indicus was administered at a dose of 500 mg/kg of body weight/day for the last 30 days of the experiment to rats with ethanol-induced liver injury, which significantly increased body weight, significantly decreased the liver/body weight ratio, AST, ALT, ALP, GGT, and LDH activities, and also the levels of TBARS, LOOH, and CD, significantly elevated the activities of SOD, CAT, GPx, and GSH in plasma, erythrocytes, and liver, and also increased levels of plasma and liver vitamin C and vitamin E at the end of the experimental period as compared to those of untreated ethanol-administered rats. Thus, our data indicate that treatment with H. indicus extract offers protection against free radical-mediated oxidative stress in plasma, erythrocytes, and liver of animals with ethanol-induced liver injury.     

The protective effect of glycyrrhizin against injury of the liver caused by ischemia-reperfusion

Effects of glycyrrhizin (GR) on an injury of the liver caused by ischemia-reperfusion in rats were determined. In the liver ischemia-reperfusion model, levels of serum AST, ALT and LDH, lipid peroxides in the liver tissue, and blood superoxide dismutase activity were significantly increased. On the contrary, total glutathione content in the liver tissue was decreased. When rats were given GR 100 mg/kg for 10 days, GR suppressed the elevation of the lipid peroxide level, serum AST, ALT, LDH level, and the decrease in glutathione content during the period of reperfusion. The suppressive effect of GR was similar with that of -tocopherol (VE). GR showed neither 1,1-diphenyl-2-picrylhydrazyl (DPPH) nor 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OOH radical-trapping ability, but exhibited DMPO-OH radical-trapping action, while, VE exhibited both DPPH and DMPO-OOH radical-trapping ability. These results indicate that the hydroxyl radical trapping action of GR is the likely mechanism suppressing liver injury caused by ischemia-reperfusion.     

Protective effects of extracts of Vernonia amygdalina, Hibiscus sabdariffa and vitamin C against radiation-induced liver damage in rats

The radioprotective efficacy of methanolic extracts of leaves of Vernonia amygdalina (VA) and Hibiscus sabdariffa (HS), and vitamin C (VIT C) against gamma radiation (4 Gy) induced liver damage was studied in male Wistar albino rats. VIT C was administered at a dose of 250 mg/kg body weight, while VA and HS were administered at doses; 200, 400 and 800-mg/kg body weight, orally for 4 weeks prior to radiation and 5 weeks after irradiation. The rats were sacrificed at 24 hours and 5 weeks after irradiation. Treatment with VIT C and VA (800 mg/kg) significantly (p < 0.05) decreased the gamma radiation-induced increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities at 24 hours after irradiation, whereas, HS (400 mg/kg) significantly (p < 0.05) decreased the serum ALT activity only. Similarly, treatment with VIT C and VA (800 mg/kg) significantly (p < 0.05) decreased the serum conjugated bilirubin levels by 56% and 29%, respectively at 24 hours. Furthermore, VIT C, VA and HS significantly (p < 0.05) decreased the levels of serum lipid peroxidation (LPO) and increased the hepatic superoxide dismutase (SOD) activities at 24 hours. Treatment for 5 weeks after irradiation with VITC, VA and HS significantly (p < 0.05) decreased the levels of unconjugated bilirubin, while VIT C and VA alone decreased the levels of conjugated bilirubin. Furthermore, treatment with VA (400 and 800 mg/kg) decreased the serum ALT activities by 25% and 34%, respectively, at 5 weeks after irradiation. Similarly, alkaline phosphatase and LPO levels were significantly (p < 0.05) attenuated following treatment with VIT C and VA (400 and 800 mg/kg) at 5 weeks after irradiation. In addition, treatment with VIT C, VA (800 mg/kg) and HS (400 and 800 mg/kg) significantly (p < 0.05) elevated the levels of reduced glutathione (GSH) by 61%, 56%, 41% and 44%, respectively, at 5 weeks. Similar elevation of antioxidant enzymes; SOD, glutathione-s-transferase and catalase were obtained in animals treated with VIT C and extracts at 5 weeks. Taken together, the results suggest that the extracts of VA and HS, and VIT C could increase the antioxidant defense systems and may probably protect animals from radiation-induced liver damage.     

4种富硒植物预防MNNG诱发大鼠胃癌效果研究 二、不同源硒预防大鼠胃癌的安全性对比研究

目的对比研究长期摄入高剂量不同源硒的安全性。方法以亚硒酸钠为对照硒材料,采用N-甲基-N′-硝基-N-亚硝基胍(MNNG)诱发大鼠胃癌模型,连续灌以4种不同富硒植物(高剂量硒)17周,测定肝脏谷胱甘肽硫转移酶(GST)、血清谷草转氨酶(AST)和血清谷丙转氨酶(ALT)活性,并观察肝脏和肾脏的病理变化。结果各组大鼠肝GST活性均无显著性差异;75μg/kg bw(以Se计,下同)亚硒酸钠低剂量组大鼠血清AST和ALT活性不仅显著高于空白对照和MNNG组,而且显著高于150μg/kg bw和300μg/kg bw植物硒处理组(P<0.05)。病理分析发现75μg/kg bw亚硒酸钠低剂量组胆管周围有棕黄色颗粒,窦内枯否氏细胞轻度肥大、增生;其余各组未发现有意义的病变。结论亚硒酸钠毒性至少是实验用其它富硒植物的4倍。     

竹荪多糖早期和晚期干预对砷中毒大鼠肝功能的影响

目的探讨砷致肝损伤大鼠体内砷含量和肝功能受竹荪多糖干预的影响。方法 108只成年清洁级SD大鼠随机分为正常对照组(24只,以普通饲料喂饲)、砷+竹荪同时干预组[(简称同时干预组),24只,10 mg/ml的竹荪多糖每日20ml/kg灌胃,且饲料中砷含量为50 mg/kg]、砷染毒组(60只,喂饲砷含量50 mg/kg的饲料),均雌雄各半。采用喂饲法进行染毒3个月后,以HE、Masson染色观察肝损伤情况。继续将砷染毒组随机均分为砷染毒组、砷+二巯基丙磺酸钠(DMPS)组[(简称DMPS组),每天以5 mg/kg二巯基丙磺酸钠腹腔注射,连续3 d,间隔4 d为一个周期]、砷+竹荪后干预组[(简称竹荪后干预组),10 mg/ml竹荪多糖每日20 ml/kg灌胃],每组18只,雌雄各半,三组均以砷含量为50 mg/kg的饲料喂饲,各组再处理3个月,观察大鼠体内砷含量和肝功能的变化情况。结果肝脏HE、Masson染色显示,与正常对照组比较,同时干预组、砷染毒组光镜下肝组织均有不同程度肝损伤出现。与正常对照组相比,各处理组大鼠血清ALT和AST的活力升高,且随着染毒时间的增加,各组大鼠血清ALT和AST的活力呈上升趋势。与正常对照组相比,各处理组大鼠血、尿、肝脏砷含量均增高(P0.05)。与砷染毒组相比,同时干预组、DMPS组、竹荪后干预组肝砷降低,血砷和尿砷升高(P0.05)。与DMPS组相比,同时干预组肝砷先降低后升高,尿砷先升高后减低,血砷先升高后减低再升高(P0.05)。与同时干预组相比,竹荪后干预组肝砷升高,血砷、尿砷降低(P0.05)。与竹荪后干预组相比,DMPS组肝砷降低,尿砷升高,血砷先升高后降低(P0.05)。结论竹荪多糖早期干预能减轻砷中毒大鼠肝损伤程度,且竹荪在砷中毒早期干预对肝损伤的减轻效果优于砷中毒后再干预,但竹荪多糖对砷中毒大鼠体内驱砷效果仍不及二巯基丙磺酸钠。     

Effect of zinc deficiency on the accumulation of metallothionein and cadmium in the rat liver and kidney

The effects of zinc (Zn) deficiency and repeated exposure to cadmium (Cd) on the accumulation and distribution of metallothionein (MT), Cd and Zn in the liver and kidney were studied. Male Sprague-Dawley rats were fed either a Zn-deficient (1 ppm) or a Zn-adequate (40 ppm) diet during the experiment, and the rats were injected subcutaneously with a cadmium chloride solution (1.0 mg Cd/kg of body weight, 5 days a week) for 4 weeks. Cadmium, Zn, and Cd-induced MT concentrations in the liver and kidney were lower in the Zn-deficient rats (–Zn + Cd) than in the Zn-adequate rats (+ Zn + Cd), while the content of Cd bound to high molecular weight proteins (HMWP) was greater in the Zn-deficient rats (–Zn + Cd). The Zn bound to Cd-induced MT was reduced to 30% in the liver and to 60% in the kidney of the Zn-deficient rats (–Zn + Cd) as compared with that of the Zn-adequate rats (+ Zn + Cd). In the kidney of Zn-deficient rats, exposure to Cd caused a decrease in essential Zn associated with HMWP as compared with that of Zn-adequate rats (+ Zn + Cd). Thus, Zn-deficiency affected the distribution of Cd in tissues, MT and HMWP and accelerated substantially Cd-induced Zn-deficiency in the kidney. Although the renal Cd concentration was lower in the Zn-deficient rats (–Zn + Cd) than in the Zn-adequate rats (+ Zn + Cd), exposure to Cd for four weeks resulted in glucosuria and an increase in liver and kidney weights in the Zn-deficient rats (–Zn + Cd), but not in the Zn-adequate rats (+ Zn + Cd). These results suggest that development of Cd toxicity is related to the Zn status of the body, to the accumulation of Cd in HMWP and to the amount of essential Zn associated with HMWP.     

Hepatotoxic activity of toluene inhalation and protective role of melatonin

This study was designed to investigate the harmful effects of toluene inhalation in the liver of rats and possible protective effects of melatonin on these detrimental effects. For this purpose, 21 adult male Wistar-albino rats were randomly divided into three equal groups. Animals in group I were used as control. The rats in group II were exposed to toluene (3000 ppm/1 hour/day) for 4 weeks, while the rats in group III were treated with melatonin (10 mg/kg/day, intraperitoneally [ip]) plus toluene inhalation. At the end of the experimental period, liver and blood samples were taken from the decapitated animals. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin and albumin levels were determined. Liver tissue sections were stained with routine histological methods and examined under the light microscope. In addition, the sections were immunohistochemically stained using avidin-biotin-peroxidase method for determination of apoptosis. The liver tissue activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) levels were also measured. Toluene inhalation significantly increased serum ALT, AST and tissue MDA, and decreased serum albumin, but did not affect serum ALP, total bilirubin levels and tissue SOD, GSH-Px and CAT activity when compared with controls. The increases in tissue MDA and serum ALT and AST levels induced by toluene inhalation were significantly inhibited by melatonin treatment. In light microscopic observations of tissues from toluene-inhaled rats, massive hepatocyte degeneration, ballooning degeneration and mild pericentral fibrosis were observed. Bax immune reactivity was also increased significantly. Melatonin treatment decreased the balloon degeneration, fibrosis and Bax immune reactivity in the liver of toluene-inhaled rats. In view of the present findings, it is suggested that melatonin has hepatoprotective effects against toluene toxicity via primarily antioxidative properties.     

Effects of low-level cadmium in rats: influence of pretreatment with thiol-modulating agents

The effects of low-level cadmium (Cd) administration to rats on animal health, liver and kidney thiols, metallothionein, and glutathione reductase (GSSG reductase) and their modulation by cysteine (as a possible protector) and diethyl maleate (as a possible potentiator) have been investigated. Male Sprague-Dawley rats were treated with sodium or Cd acetate (25 micrograms Cd/kg) orally five times a week for 6 weeks. A second group of animals received cysteine (500 mg/kg; po) before each gavage while a third group received diethyl maleate (DEM) (0.85 mg/kg; ip) in addition to sodium or Cd acetate. When rats were treated with cadmium alone neither weight gain nor serum parameters indicative of hepato- or nephro-toxicity were affected. However, acid-soluble thiols, primarily glutathione, were decreased by about 25% in liver only. A tendency to a decrease in hepatic protein thiols was also noted. No changes were observed for hepatic or renal metallothionein in response to this low level of cadmium administration alone or in combination with the other treatments. Animals receiving cysteine, either alone or with cadmium, showed decreased body weight gain, but no change in serum parameters. Acid-soluble thiols in liver were lower in cysteine-treated rats (24%) and cysteine + Cd (33%) while kidney thiols were unaffected. Administration of DEM alone or with Cd did not cause any alteration in body weight gain. When given DEM + Cd, however, an increase in serum bilirubin was observed, which suggests interference with hepatobiliary function. Acid-soluble thiols were decreased by DEM alone (45%) and DEM + Cd (51%) in liver while renal thiols showed no change. Our data indicate that low-level Cd gavage decreases hepatic cellular thiols but not those of kidney. Cysteine gavage does not protect from the Cd-related effect. Indeed, cysteine itself was found to reduce acid-soluble thiols under the experimental conditions. This was observed only in liver, as was the decrease in thiols due to DEM treatment. DEM administration together with Cd resulted in signs of liver toxicity. There is no indication that inhibition of GSSG reductase by Cd might be involved in the thiol-decreasing effect of short-term repeated low-level gavage of Cd to rats.     

芹菜素纳米乳对肝纤维化的治疗作用

目的 研究芹菜素纳米乳对肝纤维化大鼠的治疗作用,并对其作用机制进行初步研究.方法 采用四氯化碳(CCl4)复制大鼠肝纤维化模型,90只SD大鼠经适应性饲养1周后,随机分为6组,每组15只.正常组以2 mL/kg橄榄油皮下注射;模型组以25％CCl4橄榄油为造模剂,按2 mL/kg皮下注射;治疗组分3组,在皮下注射25％CCl4橄榄油的同时灌胃给予芹菜素纳米乳25、50、100 mg/kg,1次/d;阳性对照组给予造模剂的同时给予水飞蓟宾100 mg/kg.每周造模2次(间隔2d),连续8周.末次给药后24 h,取大鼠血清和肝脏,观察芹菜素纳米乳对大鼠血清肝功能指标ALT和AST,肝纤维化指标透明质酸(HA)、层黏连蛋白(LN)、Ⅳ型胶原(Ⅳ-C)、Ⅲ型前胶原(PCⅢ)和肝组织中丙二醛(MDA)、羟脯氨酸(Hyp)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px),转化因子-β1(TGF-β1)、金属蛋白酶抑制因子-1(TIMP-1)、α-平滑肌肌动蛋白(α-SMA)表达的影响.结果 芹菜素纳米乳能显著降低ALT、AST、LN、PCⅢ、Ⅳ-C水平(F=13.851、6.877、5.352、7.469、20.874,P均＜0.01),升高SOD和GSH-PX活性,降低Hyp含量(F=5.470、20.734、195.76,P均＜0.01),显著降低TIMP-1、TGF-β1和α-SMA的表达(F=82.281、72.359和91.226,P＜0.01).结论 芹菜素纳米乳对CC14致肝纤维化大鼠具有一定的治疗作用,其作用机制可能与抗脂质过氧化反应、影响TGF-β1、TIMP-1、α-SMA表达有关.     

Organ and subcellular distribution of cadmium in rats exposed to cadmium, mercury, and selenium

Four groups of rats were given: cadmium chloride (Cd), cadmium chloride and mercuric chloride (Cd + Hg), cadmium chloride and sodium selenite (Cd + Se), or cadmium chloride, mercuric chloride, and sodium selenite (Cd + Hg + Se). All animals received subcutaneous doses of 115mCdCl2 (0.3 mg Cd/kg) every other day for 2 weeks. Mercuric chloride was administered intravenously at doses of 0.5 mg Hg/kg every other day, and Na2 75SeO3 intragastrically at doses of 0.1 mg Se/kg every day for a fortnight. The whole-body and organ retention of cadmium changed slightly with the type of exposure. A significant interaction effect of the examined elements was noted in the nuclear and soluble fractions of the liver and kidneys. Mercury decreased the cadmium concentration in both the nuclear and soluble fractions of the kidneys and diminished the effect of selenium on the cadmium level in the soluble fraction of the kidneys. In the liver the presence of mercury contrary to selenium, lowered the cadmium level in the nuclear fraction. The pattern of cadmium binding to proteins of the soluble fraction of the kidneys and liver remained the same in all groups of animals.     

Biochemical Response of the Copepod <Emphasis Type="Italic">Tigriopus japonicus</Emphasis> Mori Experimentally Exposed to Cadmium

The response of the copepod (Tigriopus japonicus Mori) to cadmium (Cd) additions was investigated under laboratory-controlled conditions in a 12-day exposure. Superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), acetylcholinesterase (AchE), reduced glutathione (GSH), the ratio of reduced to oxidized glutathione (GSH/GSSG), and metallothionein (MT) were analyzed for Cd treatments (0, 10, 20, 40, and 100 μg/L) after exposure for 1, 4, 7, and 12 days. Additionally, thiobarbituric reactive species assay was used to evaluate lipid peroxidation (LPO) of the copepod after the 12-day exposure. The results indicated that Cd treatments significantly influenced the biochemical indexes (SOD, GPx, GST, AchE, GSH, and GSH/GSSG) after certain exposure times. Exposure to Cd induced LPO in the treated copepods, hinting that the copepods had suffered from oxidative damage. During exposure, the Cd initiated an induced MT synthesis in the copepods by day 7, which peaked at day 12 and which was probably responsible for Cd detoxification. Thus, Cd exposure significantly affected the detoxification process and antioxidant system of this copepod, and T. japonicus could be used as a suitable bioindicator of exposure to Cd using SOD, GPx, GST, LPO, and GSH/GSSG as biomarkers.     

金属硫蛋白排铅和肝脏保护作用的实验研究

目的探讨金属硫蛋白(metallothionein,MT)对染铅小鼠的排铅作用以及对肝脏的保护作用。方法小鼠连续30d饮用0.55g/L醋酸铅水溶液制作铅中毒模型组,以MT灌胃的小鼠作为治疗组,并以依地酸二钠钙作为阳性药物对照组。结果MT组小鼠股骨铅含量为(8.50±4.53)μg/g,明显低于铅模型组(P<0.05);MT组小鼠血清中丙氨酸氨基转移酶(ALT)为(27.44±3.43)U/L,明显低于铅模型组(P<0.05),但肝脏中ALT为(232.83±18.08)U/L,明显高于铅模型组(P<0.05)。MT组、正常组和铅模型组小鼠血清和肝脏中的天冬氨酸氨基转移酶(AST)比较,差异无统计学意义(P>0.05);染铅小鼠肝细胞膜Na+-K+ATP酶和Ca2+-Mg2+ATP酶活力没有明显变化。结论MT具有明显的促排铅作用;但对肝脏的保护作用不明显。     

紫苏提取物对化学性肝损伤保护作用的研究

目的研究紫苏提取物(Perilla frutescens extract,PE)对急性化学性肝损伤的保护作用。方法80只雄性KM小鼠(体重20±2g)随机分为8组:正常对照组(NC),模型对照组(MC),阳性药联苯双酯(DDB)组(200mg/kg),迷迭香酸(rosmarinic acid,RAD)低、高剂量预防组(11、44mg/kg),PE低、中、高剂量预防组(30、60、120mg/kg)。NC、MC组灌胃生理盐水,其它各组灌胃同等容量的相应药物,每天给药1次。实验20d后,用四氯化碳(CCl4 0.05ml/kg)和乙酰氨基酸(APAP 250mg/kg)腹腔注射分别制作急性化学性肝损伤模型。测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性、甘油三酯(TG)含量,肝组织匀浆超氧化物岐化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性、丙二醛(MDA)含量,并观察肝脏病理改变。结果PE(120mg/kg)能显著降低CCl4与APAP诱导的肝损伤小鼠血清ALT、AST活性、TG含量,升高肝脏SOD、GSH-Px活性,降低MDA含量能明显减轻肝组织损伤程度;PE对正常小鼠血清ALT、AST、TG无影响。结论PE对CCl4或APAP诱导的小鼠急性化学性肝脏氧化损伤具有显著保护作用。     

The tissue disposition of zinc and copper following repeated administration of cadmium and selenium to rats

Female rats were divided into four groups of five rats each including one control group (C). The animals were administered Na2SeO3 (Se), (CdCl2 Cd), and Na2SeO3 + CdCl2 (Cd + Se). Sodium selenite was given intragastrically at a dose of 0.5 mg Se/kg every day and cadmium chloride was injected subcutaneously every other day at a dose of 0.3 mg Cd/kg for 2 weeks. Exposure of rats to Cd caused an increase in the concentration of copper in the kidneys, blood, and liver and a decrease in the lung, but increased the concentration of zinc in the liver and brain and diminished it in the muscles and bones. In animals exposed to Se an increase in the copper concentration was observed in blood and brain; zinc was increased in the blood, heart, brain, and stomach, but decreased in the kidneys. Exposure of rats to Cd + Se resulted in an increase of copper in the kidneys and a decrease in the spleen, lungs, stomach, muscles and bones. Se prevented the cadmium-induced diminution of the zinc levels in the muscles and bones.     

补充抗氧化剂对急性肝损伤大鼠肝星型细胞zf-9mRNA表达的影响

目的:探讨经膳食补充抗氧化剂维生素E(VE)、硒及槲皮素对大鼠急性肝损伤早期肝脏星型细胞激活相关性基因zf-9mRNA表达的影响。方法:90只SD大鼠随机分为正常对照组、病理对照组、VE和硒补充组及槲皮素补充组。通过灌胃分别补充VE、Se(VE20mg/kg bw·d,硒16μg/kgbw﹒d)和槲皮素(50mg/kg bw·d)2w后,腹腔内注射CCl4造成急性肝损伤,分别于注射后的3、6、12和24h检测抗氧化状态及肝功能;用胶原酶和链霉蛋白酶灌注肝脏并分离急性肝损伤期各时间点的肝星型细胞,应用半定量聚合酶链反应(RT-PCR)研究zf-9mRNA的表达。结果:膳食补充VE、硒和槲皮素可显著减少急性肝损伤大鼠血清MDA水平,增强SOD活性,保护肝功能;下向调控肝星型细胞激活早期zf-9mRNA的表达。结论:膳食补充抗氧化剂VE、硒及槲皮素可有效地调控HSC激活相关性基因zf-9mRNA的表达。