对氨基水杨酸钠干预锰致大鼠海马神经元损伤的体外研究

目的 探讨对氨基水杨酸钠(PAS-Na)体外染锰致大鼠原代海马神经元损伤的干预作用.方法 培养至第8天的海马神经元随机分为对照组、染锰组、低、中和高剂量PAS-Na干预组(L-PAS、M-PAS、H-PAS组).对照组给予培养液培养48 h;染锰组神经元暴露于MnCl2·4H2O 50/μmol/L培养液培养24 h后...     

对氨基水杨酸钠对染锰大鼠学习记忆及海马GFAP阳性细胞表达的影响

目的 探讨对氨基水杨酸钠(PAS-Na)对亚急性染锰大鼠学习记忆及海马胶质原纤维酸性蛋白(GFAP)阳性细胞表达的影响.方法 雄性SD大鼠40只随机分为正常对照组(对照组)、染锰组、低和高剂量PAS-Na治疗组(L-、H-PAS组).染锰和PAS治疗大鼠每天腹腔注射(ip)MnCl2·4H2()15 mg/kg,对照组...     

亚急性1,2-二氯乙烷染毒对小鼠行为及脑神经递质含量的影响

目的 探讨亚急性1,2-二氯乙烷(1,2-dichloroethane,1,2-DCE)染毒对小鼠行为及脑神经递质含量的影响,为揭示1,2-DCE神经毒性机制提供参考.方法 将昆明种小鼠随机分为4组:对照组和低、中、高剂量1,2-DCE染毒组(225、450、900 mg/m3),每组8只小鼠,静式吸入染毒10 d,每天染毒3.5 h.最后一次染毒结束后立即进行旷场试验,实验结束后处死小鼠,快速取大脑组织,采用高效液相色谱法(HPLC)检测脑组织中谷氨酸(Glu)、天冬氨酸(Asp)及γ-氨基丁酸(GABA)的含量.结果 各染毒组小鼠脑组织中Asp和Glu含量随染毒剂量的增加而升高,且各染毒组小鼠的Glu含量[低、中、高剂量染毒组分别为(67.69±9.89)、(67.99±6.23)、(71.16±5.96)μmol/g Pro]与对照组[(50.78±5.15)μmol/g Pro]比较,差异均有统计学意义(P<0.01);低剂量染毒组小鼠脑组织中GABA含量[(8.08±2.37)μmol/g Pro]较对照组[(12.83±3.36)μmol/g Pro]明显降低,但高剂量组[(19.87±5.30)μmol/g Pro]与对照组比较,明显升高,差异均有统计学意义(P<0.05,P<0.01).低剂量1,2-DCE染毒对小鼠的行为有兴奋作用;而高剂量1,2-DCE染毒对小鼠的探索性及运动性行为有抑制作用.结论 亚急性1,2-DCE染毒可引起小鼠脑组织中氨基酸类神经递质含量及比值的变化,进而导致出现行为的改变,这可能是1,2-DCE神经毒性作用的机制之一.

Abstract：

Objective To explore the effects of 1,2-dichloroethane (1,2-DCE) on the behavior and the brain neurotransmitter levels in mice.Methods Thirty mice were randomly divided into four groups,which were control group and groups of low,meddle and high exposure (225,450 and 900 mg/m3) to 1,2-DCE for 10 days (3.5 h a day) by inhalation.After the last exposure,the open field test was performed immediately.After exposure all mice were killed and the brain tissues were taken up rapidly.The levels of aspartate (Asp),glutamate (Glu) and gamma-aminobutyric acid (GABA) in the brain were detected by high performance liquid chromatography (HPLC ).Results Levels of Asp and Glu in all exposure groups increased with doses.As compared to the control group,levels of Glu in all exposure groups increased significantly (P<0.05 ).Levels of GABA in the low exposure group were significantly lower than those in control group,but those in the high exposure group were significantly higher than those in control group.The results of the open field test showed that effect of low exposure to 1,2-DCE on the behavior was stimulant,but the high exposure to 1,2-DCE inhibited behavior of exploration,excitement and sport.Conclusions Subacute exposure to 1,2-DCE could result in the change of amino acid neurotransmitter content and ratio in the brain,thereby change the behavior of mice appeared,which might be the mechanism of neurotoxicity caused by 1,2-DCE in part.     

孕哺期铝暴露对仔鼠海马 N-甲基-D-天门冬氨酸受体表达的影响

目的 研究孕哺期染铝对仔鼠学习记忆和仔鼠海马组织中N-甲基-D-天门冬氨酸受体(NMDAR)表达的影响,以探讨铝对发育中的中枢神经系统的毒性作用及机制.方法 Wistar大鼠60只,雌雄各半,饲养1周后按1∶1雌雄合笼,发现阴栓即可认为雌鼠怀孕,按体重将孕鼠随机分为3组:对照组(饮用蒸馏水)、低剂量组(饮用0.2%AlCl3蒸馏水溶液)、高剂量组(饮用0.4%AlCl3蒸馏水溶液),每组10只,母鼠从怀孕开始染毒,至仔鼠哺乳期(出生后21 d)结束,共染毒6周.原子吸收石墨炉法测 定血铝和脑铝含量;跳台试验法观察大鼠学习、记忆行为学的改变;用免疫印迹(Western blot)法测定海马NMDA受体表达水平.结果 随着染铝剂量的增加,仔鼠血铝、脑铝含量明显增加,与对照组比较,差异有统计学意义(P＜0.05).低、高剂量染铝组仔鼠跳台试验的潜伏期逐渐缩短[分别为(202.71±81.99)、(19.67±8.44)s],与对照组[(300.00±0.00)s]比较,差异有统计学意义(P＜0.01),而错误次数逐渐增加(低、高剂量染铝组分别为1.43±0.85、2.47±0.99),与对照组(0.00±0.00)比较,差异有统计学意义(P＜0.01).铝暴露也可导致NMDAR各亚型的比例发生变化,低、高剂量染铝组仔鼠海马组织中NR1和NR2B含量下降(低剂量染铝组NR1和NR2B灰度值为25.22±0.68、81.23±15.37,高剂量染铝组NR1和NR2B灰度值为24.75±0.71、56.63±7.82,与对照组(NR1和NR2B灰度值分别为31.69±3.44、107.61±9.05)比较,差异均有统计学意义(P＜0.05).结论 孕哺期铝暴露可以引起发育中大鼠学习记忆能力下降,导致NMDAR各亚型的比例发生变化,NR1和NR2B含量下降可能是母体铝暴露影响子代大鼠学习记忆能力的重要分子机制之一.

Abstract：

Objective To investigate the effects of aluminum on learning and memory and the expression of N-methyl-D-aspartic acid receptor (NMDAR) of hippocampus in offspring from female rats exposed to Al in the pregnancy or lactation, and to explore the mechanism of toxic effects of Al on central nervous system (CNS) during development. Methods The pregnant Wistar rats were randomly divided into 3 groups based on their body weight, I.e. Control group was exposed to distilled water, low exposure group (0.2 %AlCl3) and high exposure group (0.4 %AlCl3) were exposed orally to AlCl3 in pregnancy and lactation for 6 weeks, 10 rats each group. Aluminum content in blood and brains was determined by atomic absorption spectrophotometry (AAS). Platform experiment was used to detect the abilities of learning and memory. The expression levels of NMDARs were detected by western blot assay. Results The Al content in blood and brains of rats in exposure groups increased significantly with Al dose, as compared with the control group ( P＜0.05 ). In platform experiment, the incubation periods of rats in low and high exposure groups were (202.71±81.99 ) and ( 19.67±8.44 )s respectively, which were significantly lower than that [( 300.00±0.00 )s] in control group (P＜0.01), but the mistake times of rats in low and high exposure groups were 1.43±0.85 and 2.47±0.99 respectively, which were significantly higher than that (0.00±0.00) in control group (P＜0.01). The Al exposure could change the proportion of NMDAR subtypes, the expression levels of NR1 and NR2B in hippocampus of newborn rats in low and high exposure groups were 25.22±0.68, 81.23±15.37 and 24.75±0.71, 56.63 ±7.82, respectively, which were significantly lower than those (31.69±3.44, 107.61±9.05 ) in control group (P＜0.05). Conclusion Aluminum exposure in pregnancy and lactation could reduce theabilities of learning and memory in newborn rats, and change the proportion of NMDAR subtypes. The reduced NR1and NR2B expression levels may be one of important mechanisms to influence the abilities of learning and memory in offspring.     

大剂量N-乙酰半胱氨酸对染尘大鼠肺组织的影响

目的 观察大剂量N-乙酰半胱氨酸(NAC)对矽肺形成过程中炎症和纤维化反应的影响.方法 将Wisar大鼠随机分为模型组、干预组、对照组,每组32只.模型组和干预组以二氧化硅结晶体诱发染尘大鼠模型,干预组以大剂量NAC进行干预.分别在染尘后的第3、7、14、28天处死8只大鼠.对大鼠肺组织进行HE染色及Masson染色,观察肺组织病理变化.用酶联免疫法(EusA)测定肺泡灌洗液中肿瘤坏死因子-α(TNF-α)和白细胞介素-8(IL-8)的含量.结果 NAC干预组病理观察显示,肺泡炎症和纤维化程度均较模型组明显减轻.与模型组(13.84±1.61、9.23±0.87、11.23±1.25、9.56±0.76)比较,第3、7、14、28天十预组肺脏系数(9.30±0.78、6.29±0.74、7.63±0.88、6.06±1.16)均明显降低.差异有统计学意义(P＜0.01.与对照组相比,各时间点模型组肺泡灌洗液中TNF-α和IL-8含量均明显升高,差异有统计学意义(P＜0.01);与模型组相比,各时间点干预组的TNF-α和IL-8含量均明显降低,差异有统计学意义(P＜0.01).结论 早期大剂量NAC干预能够明显减轻染尘大鼠的肺组织炎症,降低肺泡灌洗液中TNF-α和IL-8含量,抑制和延缓肺纤维化的发生.

Abstract：

Objective To explore the effects of high-dose N-acetylcysteine on the lung tissues of rats exposed to silica. Methods Ninety-six Wistar rats were randomly divided into model group, intervention group and control group (32 rats for each group). The rats of model group and intervention group were exposed to silica by intratracheal infusion of silica dust suspension. The rats in the intervention group were orally given high dose N-acetylcysteine. In 3,7,14,28 days after exposure, eight rats in each group were sacrificed, respectively and the lung samples were collected. The pathological changes of lung were evaluated by HE and Masson staining methods. The levels of TNF-α and IL-8 in the BALF were detected by ELISA. Results Compared with the control group, the alveolitis and pulmonary fibrosis in the intervention group were significantly reduced. In 3,7,14,28 days after exposure, the lung/body coefficients in the intervention group were 9.30±0.78, 6.29±0.74,7.63±0.88,6.06+1.16 respectively, which were significantly lower than those (13.84±1.61,9.23±0.87, 11.23±1.25,9.56±0.76, P＜0.01 )in the model group (P＜0.01). At the different time points, the levels of TNF-α and IL-8 in the BALF in the intervention group were significantly higher than those in the control group (P＜0.01), but were significantly lower than those in the model group (P＜0.01). Conclusion The intervention with high dose N-acetylcysteine can significantly reduce the alveolitis and the TNF-α and IL-8 levels in the BALF, therefore, inhibit and delay the development of pulmonary fibrosis of rats exposed to silicon dioxide.     

过氯酸铵对大鼠甲状腺功能及其球蛋白和过氧化物酶mRNA表达的影响

目的 研究过氯酸铵(AP)对大鼠甲状腺功能及甲状腺球蛋白(Tg)、甲状腺过氧化物酶(TPO)基因mRNA表达的影响.方法 将雄性SD大鼠30只随机分为:正常对照组、低碘组(含碘量:50μg/kg)、AP染毒低(130 mg/kg)、中(260 mg/kg)、高剂量组(520 mg/kg)及AP+高碘组[AP:520 mg/kg,高碘饮水(10 mg/L)],每组5只.经口染毒90 d后处死,放射免疫法测定血清游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)及促甲状腺激素(TSH)的水平;荧光定量PCR法测定甲状腺球蛋白(Tg)、甲状腺过氧化物酶(TPO)基因mRNA表达水平.结果 AP中剂量和AP高剂量组FT4水平[(9.540±1.327)fmol/ml,(6.509±1.949)fmol/ml)明显低于正常对照组[(13.505±1.276)fmol/ml],差异有统计学意义(P＜0.05,P＜0.01).AP高剂量组的TSH水平[(1.227±0.295)mIU/L]明显高于正常对照组[(0.545±0.282)mIU/L],差异有统计学意义(P＜0.05);各AP剂量组Tg的mRNA表达相对值均明显低于正常对照组,差异有统计学意义(P＜0.01),AP高剂量组TPO基因mRNA表达相对值明显低于正常对照组,差异有统计学意义(P＜0.05).结论 AP可降低大鼠FT3、FT4水平,引起TSH反馈性增高,并明显抑制Tg和TPO基因mRNA的表达;而高碘可以在一定程度上拮抗AP对大鼠甲状腺的毒作用.

Abstract：

Objective To investigate the effects of ammonium perchlorate (AP) on thyroid functions and mRNA expression levels of thyroglobulin(Tg) and thyroperoxidase (TPO) genes of rats. Methods Thirty SD male rats were randomly divided into six groups: control group, iodine-deficient group, low dose AP group ( 130 mg/kg), moderate dose AP group (260 mg/kg), high dose AP group (520 mg/kg) and high iodinecombined group. After the rats were exposed orally for 90 days, serum free-thyroxine (FT4), freetriiodothyronine (FT3) and thyroid stimulating hormone (TSH) were measured using radioimmunoassays.mRNA expression levels of thyroglobulin (Tg) and thyroperoxidase (TPO) genes were detected by real-time quantitative PCR. Results Serum FT4 levels in moderate dose AP group and high dose AP group were [(9.540±1.327) fmol/ml] and [(6.509±1.949) fmol/ml] respectively, which were significantly lower than that [ (13.505 ±1.276 ) fmol/ml] in control group (P＜0.05 or P＜0.01). Serum TSH level in high dose AP group was [(1.227±0.295) mIU/L], which was significantly higher than that [(0.545±0.282) mIU/L] in control group (P＜0.05). The mRNA expression levels of thyroglobulin (Tg)gene in all groups exposed to AP were significantly lower than that in control group (P＜0.01). The mRNA expression level of thyroperoxidase (TPO)gene in high dose AP group was significantly higher than that in control group (P＜0.05). Conclusion AP can reduce the serum FT3 and FT4levels of rats, increase the serum TSH level of rats and decrease obviously the mRNA expression levels of Tg and TPO genes. In addition, high iodine can reduce the toxic effects of AP on thyroid gland of rats to some extent.     

对氨基水杨酸钠对锰染毒大鼠丘脑原代小胶质细胞氧化损伤及炎症反应的影响

[目的]探讨对氨基水杨酸钠(PAS-Na)对体外染锰大鼠丘脑原代小胶质细胞氧化损伤、炎症反应的影响。[方法]将提纯、鉴定后的SD大鼠丘脑小胶质细胞分别给予含不同浓度氯化锰(MnCl_2)(0、200、300、400、500μmol/L)、PAS-Na(50、150、450μmol/L)的完全培养基(DMEM+FBS)培养24 h,采用MTT法检测细胞存活率,根据结果选择染锰的毒性剂量并选定PAS-Na的无毒剂量。随后将细胞随机分为对照组、400μmol/L MnCl_2组、400μmol/L MnCl_2+(50、150、450μmol/L)PAS-Na组、450μmol/L PAS-Na组,共6组。采用MTT法检测各组小胶质细胞存活率;运用DCFH-DA探针标记,荧光倒置显微镜下观察小胶质细胞内活性氧(ROS)的产生情况;ELISA法测定炎症因子白介素(IL)-1β、IL-6、肿瘤坏死因子(TNF)-α的蛋白分泌量和荧光定量PCR法测IL-1β,TNF-αmRNA表达水平。[结果]400、500μmol/L MnCl_2染毒组的细胞存活率为(85.83±12.53)%、(83.30±6.33)%,低于对照组(均P0.05),故选择400μmol/L作为锰的染毒剂量;与对照组比较,50、150、450μmol/L PAS-Na组的细胞存活率无明显变化(均P0.05)。400μmol/L MnCl_2+(50、150、450μmol/L)PAS-Na组的细胞存活率分别为(96.00±18.11)%、(106.13±18.32)%、(110.21±15.13)%,均比400μmol/L MnCl_2组高(均P0.05)。与对照组比较,400μmol/L MnCl_2组细胞ROS水平、IL-1β和TNF-α的蛋白及mR NA表达水平均升高(均P0.05)。与400μmol/L MnCl_2组比较,400μmol/L MnCl_2+(50、150、450μmol/L)PAS-Na组的ROS水平、TNF-α分泌量和IL-1βmRNA表达量均降低(均P0.05),400μmol/L MnCl_2+(150、450μmol/L)PAS-Na组的TNF-αmRNA表达量降低(均P0.05)。[结论]PAS-Na可减轻锰致大鼠丘脑原代小胶质细胞氧化损伤、炎症反应的程度。     

五味子乙素对染矽尘大鼠肺组织转化生长因子β1信号转导通路分子mRNA表达的影响

目的 观察五味子乙素(sehisandrin B,Sch-B)对染矽尘大鼠肺组织转化生长因子β1(TGF-β1)信号通路分子mRNA表达的影响,探讨其防治矽肺纤维化的作用及机制.方法 将96只Wistar大鼠随机分为对照组、染矽尘组、Sch-B干预组,每组32只,气管暴露法一次性染尘建立大鼠矽肺模型,染矽尘组和Sch-B干预组每只大鼠气管内注入1 ml(50 mg/ml)SiO2混悬液,对照组注入1 ml灭菌生理盐水.染尘后第1天开始灌胃干预,Sch-B组给予Sch-B(80mg·kg-1/d-1),染矽尘组和对照组给予等体积的橄榄油.不同处理3、7、14和28 d后,各组处死8只大鼠,对肺组织HE染色观察病理改变;用反转录-聚合酶链式反应(RT-PCR)法测定大鼠肺组织中TGF-β1、转化生长因子βⅡ型受体(TGF-βRⅡ)和Smad4基因表达.结果 染矽尘组肺损伤明显,在3和7 d时表现为明显的肺泡炎,可见肺泡间隔水肿,大量炎性细胞浸润,在14d时,肺泡间隔明显增宽,成纤维细胞和胶原基质明显增多;在28 d时,肺泡结构破坏,肺泡壁明显增厚,肺组织以胶原沉积和肺纤维化改变为主.Sch-B组肺泡炎和肺纤维化程度均较染矽尘组明显减轻.染矽尘组3、7、14、28 d时大鼠肺内TGF-β1、TGF-βRⅡ和Smad4的mRNA表达(TGF-β1:1.03±0.31、1.33±0.39、1.08±0.26、0.82±0.16,TGF-βRⅡ:0.65±0.11、0.80±0.16、0.83±0.24、0.62±0.15,Smad4:0.87±0.15、0.68±0.11、0.78±0.19、0.30±0.08)均明显高于对照组(TGF-β1:0.59±0.22、0.55±0.25、0.56±0.20、0.55±0.12,TGR-βRⅡ:0.28±0.13、0.31 ±0.15、0.34±0.15、0.27±0.09,Smad4:0.23±0.11、0.40±0.12、0.39±0.12、0.18±0.06),差异均有统计学意义(P＜0.01或P＜0.05),其中TGF-β1在第7天时达高峰后开始下降.Sch-B干预组各时间点TGF-β1和Smad4(TGF-β1:0.68±0.28、0.88±0.25、0.75±0.11、0.61±0.14,Smad4:0.25±0.12、0.45±0.09、0.44±0.07、0.21±0.04)均低于染矽尘组,差异有统计学意义(P＜0.01或P＜0.05).与染矽尘组相比,Sch-B干预组TGF-βRⅡmRNA表达无明显改变,差异无统计学意义(P＞0.05).结论 Sch-B能减轻染矽尘大鼠肺组织的纤维化程度,其作用机制可能是通过抑制TGF-β1和Smad4的mRNA表达上调,从而干扰TGF-β1/Smad4信号通路对靶基因的激活来实现的.

Abstract：

Objective To investigate the effects of schisandrin B (Sch-B) on expression of transforming growth factor-β1 (TGF-β1) and signal transduction molecule mRNA in rat lungs exposed to SiO2,and explore the intervention mechanism of Sch-B on pulmonary fibrosis induced by SiO2. Methods Ninety six Wistar rats were randomly divided into control (normal saline) group, SiO2 group and SiO2 plus Sch-B group.The rats were exposed to SiO2 by direct tracheal instillation to establish the silicotic animal models. SiO2 group and SiO2 plus Sch-B group were treated with 1ml SiO2 (50 mg/ml) for each rat From the first day after model establishment, SiO2 plus Sch-B group were orally given Sch-B (80 mg/kg) a day, control group and silica group were orally given olive oil. On the 3rd, 7th,14th and 28th days after treatment, 8 rats in each group were sacrificed and samples were collected. The histo-pathological examination of lung was performed by HE staining. The expression levels of TGF-β1 、TGFβR Ⅱ and Smad4 mRNA in the lung tissues were detected by RT-PCR. Results The results of histo-pathological examination showed that in SiO2 group, lung tissues were injured obviously; the alveolar inflammation with alveolus interval edema and inflammation cell infiltration appeared on the 3rd and 7th days; the alveolus interval became thicker, became thicker, fibroblast and collagen matiix increased markedly on 14th day; the alveolar structure was damaged, alveolar wall thickened obviously,collagen aggradation and pulmonary fibrosis displayed on 28th day. The alveolar inflammation and pulmonary fibrosis in SiO2 plus Sch-B group were significantly less than those in SiO2 group. The expressions levels of TGF-β1、TGFβR Ⅱ and Smad4 mRNA (TGF-β1: 1.03±0.31 、1.33±0.39、1.08±0.26、0.82±0.16,TGF-βR Ⅱ:0.65 ±0.11、0.80 ±0.16、0.83 ±0.24、0.62 ±0.15, Smad4: 0.87 ±0. 15、0.68 ±0.11、0.78 ±0.19、0.30 ±0.08) in SiO2group were significantly higher than those in the control group (TGF-β1:0.59±0.22、0.55 ±0.25、0.56±0.20、0.55 ±0.12,TGR-βR Ⅱ:0.28 ±0.13、0.31 ±0. 15、0.34 ±0.15、0.27 ±0.09,Smad4:0.23 ±0.11、0.40 ±0. 12、0.39 ±0.12、0.18±0.06)(P＜0.01 or P＜0.05), but the expression level of TGF-β1 mRNA was the highest on the 7th day. The expression levels of TGF-β1 and Smad4 mRNA (TGF-β1: 0.68 ±0.28、0.88 ±0.25、0.75 ±0.11、0.61 ±0. 14,Smad4:0.25 ±0.12、0.45 ±0.09、0.44 ±0.07、0.21 ±0.04) in SiO2 plus Sch-B group were significantly lower than those in SiO2 group (P＜0.01 or P＜0.05),but there were no significant differences of the TGFβR Ⅱ mRNA expression levels between SiO2 group and SiO2 plus Sch-B group. Conclusion Sch-B can reduce the pulmonary fibrosis induced by SiO2 through inhibition of the mRNA express of TGF-β1 and Smad4 in the lung tissue, modulating the TGF-β1/Smad4 signal transduction pathway and inhibiting the target gene activation.     

RNA干扰caspase-3基因对染铝小鼠神经行为的影响

目的 研究RNA干扰caspase-3基因对染铝小鼠神经行为的影响.方法 取健康3月龄雄性昆明种小鼠,按体重随机分为4组:空白对照组(给予生理盐水4 μl)、染铝组(给予0.5%AlCl3·6H2O4μ1)、Al+空载体组(给予0.5%AlCl3·6H2O 3 μl+对照siRNA表达载体1 μl)、Al+RNAi组(给予0.5%AlCl3·6H2O 3μl+目的 siRNA表达载体1 μl),侧脑室注射连续染毒5 d,采用Morris水迷宫试验、旷场试验、跳台试验检测小鼠神经行为改变,电子显微镜观察小鼠海马病理改变,反转录-聚合酶链反应(RT-PCR)法检测caspase-3基因表达量.结果 与空白对照组[分别为(279.00±17.17)s、1.13±0.35]相比,染铝组的潜伏期(LT)[(44.67±10.60)s]明显缩短,错误次数(3.63±0.52)明显增加,Al+空载体组LT[(68.00±14.70)s]明显缩短,差异均有统计学意义(P<0.05);Al+RNAi组LT[(239.50±19.36)s]比染铝组明显延长,错误次数明显减少,差异均有统计学意义(P<0.05).与空白对照组相比,染铝组逃避潜伏期明显延长,原平台象限停留时间明显缩短,Al+空载体组逃避潜伏期明显延长,Al+RNAi组逃避潜伏期较染铝组明显延长,差异均有统计学意义(P<0.05).与空白对照组相比,染铝组和Al+空载体组小鼠中央格停留时间明显延长,直立次数、修饰次数明显减少,差异均有统计学意义(P<0.05);Al+RNAi组小鼠中央格停留时间较染铝组明显缩短,跨格次数、直立次数、修饰次数较染铝组明显增加,差异均有统计学意义(P＜0.05).空白对照组海马细胞出现轻微改变,染铝组和Al+空载体组海马细胞改变明显,Al+RNAi组海马细胞的病理形态变化减少.空白对照组海马CA3区神经细胞层次较为清楚,基本无变性损伤现象发生;染铝组和Al+空载体组小鼠CA3区细胞数量明显减少,排列不规则,神经元尼氏体着色较空白对照组浅;RNA干扰后,CA3区神经细胞数量明显增加,排列较规则,神经元尼氏体着色逐渐加深.染铝组和Al+空载体组的caspase表达量(分别为2.24±0.57、2.28±0.33)较空白对照组(1.00±0.00)明显增加,Al+RNAi组的的caspase-3表达量(0.44±0.08)较空白对照组和染铝组明显降低,差异均有统计学意议(P＜0.05).结论 铝可以引起小鼠学习和记忆能力障碍,活跃程度及探索能力下降,而RNAi技术能够在一定程度上减轻该毒性作用.

Abstract：

Objective To investigate the effects of caspase-3 siRNA on the neurobehavior of mice exposed to aluminum. Methods Male KunMing mice ( 3 months old ) were randomly divided into 4 groups by weight:blank control group(4 μl normal saline), Al group(4 μl 0.5%AlCl3), Al plus empty vector group(3 μl 0.5% AlCl3 plus control siRNA expression vector)and Al plus RNAi group (3μl 0.5% AlCl3 plus targeted siRNA expression vector). All groups were treated by lateral cerebral ventricle micro-injection for 5 days. The neurobehavior was tested by the Morris water maze test, Open-field and Step-down tests for all treated mice. Pathological changes in hippocampus was observed by electron microscopy, the caspase-3 gene expression levels were detected using RT-PCR. Results The results of Step-down test indicated that as compared with control group, the latent time [LT, (44.67±10.60) s] in Al group decreased significantly, the error number (3.63±0.52) in Al group increased significantly and the LT [(68.00±14.70) s] in Al plus empty vector group decreased significantly(P<0.05). the LT [(239.50±19.36) s] in Al plus RNAi group increased significantly and the error number in Al plus RNAi group decreased significantly, as compared with Al group (P<0.05). The results of Morris water maze test showed that as compared with control group, the LT in Al group increased significantly, and residence time in the former platform quadrant decreased significantly and the LT in Al plus empty vector group increased significantly (P<0.05). The LT in Al plus RNAi group was significantly longer than that in Al group(P<0.05). The results of open-field test demonstrated that as compared with control group, the time in the central grid in Al group and Al plus empty vector group increased significantly, the rearing number and the modification number in Al group and Al plus empty vector group decreased significantly (P< 0.05). As compared with Al group, the time in the central grid in Al plus RNAi group decreased, the inter-cell number, the rearing number and the modification number increased significantly (P<0.05). The results of electron microscopic examination exhibited that a slight change of hippocampal cells appeared in control group, the obvious pathological changes of hippocampal cells appeared in Al group and Al plus empty vector group, but the pathological changes of hippocampal cells in Al plus RNAi group significantly reduced as compared with Al group. The results of thionin staining indicared that the layers of neural cells of hippocampal CA3 were more clear and there was not obvious denatured injury of neural cells of hippocampal CA3 in control group. The number and Nissl body color of neural cells of hippocampal CA3 in Al group and Al plus empty vector group decreased significantly. After RNA interference, the number and Nissl body color of neural cells of hippocampal CA3 increased obviously. The expression levels of caspase-3 gene in Al group and Al plus empty vector group were 2.24±0.57 and 2.28±0.33, respectively, which were significantly higher than that (1.00±0.00) in control group (P<0.05). The expression level of caspase-3 gene in Al plus RNAi group was 0.44 ±0.08, which was significantly lower than those in Al group and control group (P<0.05). Conclusion Aluminum can decrease the learning and memorizing ability, and inhibited the activity or exploration function of mice. It is suggested that Caspase-3 siRNA may reduce the neurotoxicity induced by aluminum to a certain extent.     

对氨基水杨酸钠对染锰大鼠基底核GABA_AR及GAT-1表达的影响

[目的]探讨对氨基水杨酸钠（PAS-Na）对短期或亚慢性染锰大鼠基底核γ-氨基丁酸（gamma-aminobutryicacid,GABA）A受体（GABAAreceptor,GABAAR）及GABA转运载体-1（GABA transporter-1,GAT-1）表达的影响。[方法]将短期实验大鼠分为染锰组、PAS低（L-）、高（H-）剂量治疗组和对照组,观察期为7、10周;将亚慢性实验大鼠分为对照组、染锰组、PAS预防组和PAS低（L-）、中（M-）、高（H-）剂量治疗组,观察期为4、8、12、18周。用实时荧光定量聚合酶链反应（RT-PCR）、免疫印迹法（Western blot）检测大鼠脑基底核GABAAR及GAT-1表达。[结果]短期实验中,观察期7周,染锰组GABAAR蛋白表达较对照组高（P〈0.05）;观察期10周,染锰组GABAAR和GAT-1 mRNA表达较对照组低,L-PAS、H-PAS治疗组基底核GAT-1 mRNA表达较染锰组高（P〈0.05）。亚慢性实验中,观察期4周,染锰组GABAAR mRNA表达较对照组高（P〈0.05）;观察期8周,染锰组GABAAR mRNA表达较对照组低,预防组GABAAR mRNA表达较染锰组高（P〈0.05）。观察期12周,染锰组GABAAR蛋白表达较对照组高,预防组GABAAR蛋白表达较染锰组低（P〈0.05）。观察期18周,染锰组GABAAR mRNA表达较对照组低,GAT-1 mRNA表达较对照组高,H-PAS治疗组GAT-1 mRNA表达较染锰组低（P〈0.05）。[结论]短期或亚慢性锰暴露对大鼠基底核GABAAR和GAT-1 mRNA表达都有明显的毒性影响,PAS-Na对亚慢性锰暴露致GABAAR mRNA或蛋白表达改变有预防性干预作用,对锰致大鼠基底核GAT-1 mRNA表达改变有治疗性干预作用。     

PAS-Na对染锰大鼠学习记忆及海马神经微丝蛋白表达的影响

[目的]探讨对氨基水杨酸钠（PAS．Na）对染锰大鼠学习记忆功能及神经微丝蛋白（NF）表达的影响。[方法]将48只雄性sD大鼠随机分为对照组、染锰组、PAS—Na低、高剂量治疗组（L—PAS、H．PAS）四组,染锰组、L-PAS组、H—PAS组大鼠每日腹腔注射（ip）氯化锰（MnCl2·4H2O,15mg／kg）,每周5d,共3周。然后,L-PAS、H—PAS组大鼠每日分别于背部皮下注射（sc）PATS．Na100mg／kg、200mg／kg,持续5周。采用Morris水迷宫检测大鼠学习记忆能力,免疫组织化学方法检测海马齿状回颗粒细胞下层微丝蛋白（NF）阳性细胞数。[结果]染锰组逃避潜伏期、游泳总路程均比正常对照组长（P〈0．05）;H．PAS组逃避潜伏期和游泳总路程比染锰组缩短（P〈0．05）。染锰组NF阳性细胞数比正常对照组减少（P〈0．01）,H．PAS组NF阳性细胞数较染锰组增多（P〈0．01）,但是仍达不到正常对照组水平（P〈0．01）。[结论]高剂量PAS—Na对锰致学习记忆能力及海马颗粒细胞受损可能有作用。     

二巯丙磺钠对溴苯腈急性中毒小鼠中枢神经毒性作用的干预

目的 研究溴苯腈急性染毒对小鼠大脑皮层中γ-氨基丁酸(GABA)和谷氨酸(Glu)含量等指标的影响及二巯丙磺钠(Na-DMPS)的作用.方法 将30只ICR小鼠(雌雄各半)随机分成对照组和染毒组,每组10只.对照组予体积分数为10%的DMSO溶液(20ml/kg)灌胃;染毒组予溴苯腈(200mg/kg)灌胃染毒;Na-DMPS保护组予溴苯腈(200mg/kg)灌胃染毒后,即刻以Na-DMPS(300mg/kg)腹腔注射.观察6 h后处死,采用反相高效液相色谱法测定各组小鼠大脑皮层中GABA、Glu含量,同时采用紫外分光光度计比色法等方法测定大脑皮层中谷氨酰胺(Gln)含量及谷氨酰胺合成酶(GS)、谷氨酸脱羧酶(GAD)、γ-氨基丁酸转氨酶(GABA-T)的活力.结果 与对照组[GABA为(3.41±0.12)μmol/g、Glu为(14.00±0.16)μmol/g、Gln为(1.25±0.19)μmol/g、GAD为(13.50±0.25)μmol·g-1·h-1、GABA-T为(25.51±0.21)μmol·g-1·h-1、GS为(142.19±1.31)U/mgpro]比较,急性中毒组小鼠大脑皮层GABA[(3.14±0.14)μmol/g]含量降低,Glu[(17.54±0.40)μmol/g]和Gln[(3.35±0.27)μmol/g]含量增高,GAD[(11.93±0.15)μmol·g-1·h-1]、GABA-T[(24.15±0.22)μmol·g-1·h-1]、GS[(140.75±1.01)U/mg pro]活力下降,差异均有统计学意义(P＜0.05);与急性中毒组相比,Na-DMPS组GABA[(3.52±0.30)μmol/g]含量升高,Glu[(14.20±0.32)μmol/g]和Gln[(1.32±0.17)μmol/g]含量降低,GAD[(13.01±0.45)μmol·g-1·h-1]、GABA-T[(25.19±0.26)μmol·g-1·h-1]、GS[(142.35±1.20)U/mgpro]活力增强,差异均有统计学意义(P＜0.05);Na-DMPS保护组与对照组相比,大脑皮层中GABA、Glu、Gln含量,GAD、GABA-T、GS活力,差异均无统计学意义(P＞0.05).结论 溴苯腈中毒所致小鼠中枢神经的毒性作用可能与大脑皮层组织中GABA和Glu含量的变化有关,Na-DMPS能改善溴苯腈中毒小鼠大脑皮层组织中GABA和Glu含量.     

对氨基水杨酸钠对染锰大鼠肝和血清酶的影响

本文观察了80mg/kg和120mg/kg的PAS-Na对染锰大鼠肝和血清几种酶活性的影响。结果表明,两种剂量的PAS-Na能恢复肝ATPase(分别为95%和97%)以及血清ACP活性(分别为112%和83%);高剂量的PAS-Na有恢复血清AChE活性(89%)的作用。PAS-Na还能驱除肝锰。     

锰对新生鼠肝组织微量元素的影响

目的研究大鼠染锰后对其子代新生鼠肝组织内微量元素的影响。方法 :将妊娠雌性大鼠随机分为 4组 ,腹腔注射氯化锰 ,剂量分别为 0、7.5、1 5和 30 mg/kg,待其自然分娩后采用原子吸收光谱法测定子代新生鼠肝组织内微量元素锰、铜、锌和铁含量。结果 :与对照组相比 ,实验各组肝组织内锰含量明显增高 ( P<0 .0 1 ) ;锌含量则低于对照组 ( P<0 .0 5,P<0 .0 1 ) ;实验各组铜含量与对照组间差异无显著性 ( P>0 .0 5) ;1 5mg/kg和 30 mg/kg组铁含量高于对照组 ( P<0 .0 5,P<0 .0 1 )。结论 :大鼠孕期染锰 ,使其新生鼠肝组织内锰、锌、铁等微量元素的含量发生明显变化 ,影响了锰、锌、铁在体内的代谢 ,从而对其子代的生长发育可能产生不利影响     

锰对大鼠纹状体谷氨酸代谢的影响

[目的]观察锰对大鼠脑谷氨酸代谢的影响。[方法]Wistar大鼠24只,按体重随机分成4组,每组6只。第1组为对照组,皮下注射0．9％氯化钠,第2～4组为锰染毒组,分别皮下注射8、40、200μmol／kg的氯化锰溶液,注射容量均为5mL／kg,染毒4周,每周5次。测定脑纹状体谷氨酰胺酶（PAG）、谷氨酰胺合成酶（GS）活性和谷氨酸（Glu）、谷氨酰胺（Gln）含量以及细胞凋亡率。[结果]染锰4周后,随着染锰剂量的增加,PAG活性逐渐升高,而GS活性逐渐下降;同时Glu含量也逐渐升高,Gln含量逐渐下降;脑纹状体细胞凋亡率明显升高（P〈0．01）。[结论]锰可以通过增强PAG活性和抑制GS活性,使Glu．Gln循环代谢紊乱,产生神经毒性。     

茶多酚对高蛋氨酸饮食诱导大鼠纤维蛋白溶解功能损伤的影响

目的 研究茶多酚( tea polyphenols,TP)对蛋氨酸诱导大鼠纤维蛋白溶解功能损伤的保护作用。方法 取成年雄性Wistar大鼠50只,按体重分层随机分为对照组、模型组,以及TP低、中和高剂量组。对照组喂饲正常基础饲料,模型组及TP组均喂饲3％高蛋氨酸饲料,同时TP低、中、高剂量组每天经灌胃分别给予50、100和200 mg/kg的TP,灌胃体积均为0.5ml/100 9,对照组和模型组给予等体积蒸馏水。8周后断头处死大鼠,采用免疫组织化学链霉亲和素-生物素-过氧化物酶复合物（strept-avidin-biotin complex,SABC）法测定大鼠主动脉弓组织型纤溶酶原激活物（tissue-type plasminogen activator,t-PA）和纤溶酶原激活物抑制剂-1（type-1 plasminogen activator inhibitor,PAI-1）蛋白表达结果;ELISA法测定血浆中t-PA和PAI-1含量;RT-PCR法测定胸主动脉t-PA和PAI-1 mRNA水平。结果 实验结束后,对照组、模型组及TP低、中、高剂量组主动脉弓中t-PA蛋白表达量分别为133.03±10.14、95.46±11.08、111.97±11.91、130.23±10.80、139.39±9.41 (F= 14.15,P＜0.01),PAI-1蛋白表达量分别为90.91±8.67、166.76±12.18、139.63±12.71、134.66±13.19、109.49±10.82(F=31.44,P＜0.01);血浆中tPA含量分别为(10.69±1.26)、(6.13±0.92)、(8.56±1.19)、(9.69±0.92)、(11.97±1.08) ng/ml(F=41.98,P＜0.01),PAI-1含量分别为(6.31±0.81)、(16.98±1.27)、(11.39±0.82)、(8.46±0.67)、(8.08±0.91) ng/ml(F= 207.74,P＜0.01);t-PA mRNA水平分别为1.12±0.02、0.75±0.14、1.01±0.09、0.95±0.08、1.05±0.13(F=5.77,P＜0.05);PAI-1 mRNA水平分别为1.25±0.11、1.74±0.06、1.23±0.05、1.09±0.14、1.23±0.04(F=23.56,P＜0.01)。结论 TP能够调节t-PA和PAI-1的转录及蛋白水平,维持t-PA和PAI-1的平衡状态,修复高蛋氨酸饮食诱导的大鼠纤维蛋白溶解功能损伤。     

谷氨酸和谷氨酰胺对大鼠学习记忆的影响

为了观察谷氨酸(Glu)和谷氨酰胺(Gln)对大鼠学习记忆的影响并探讨其机理,选用Wistar大鼠36只,随机分为3组:对照组、Glu 组和Gln 组,分别给予普遍饲料、补充2% Glu 和2% Gln 的饲料喂养2周后,以穿梭箱实验作为学习记忆的行为模型对大鼠进行训练,记录主动回避反应次数和被动逃避时间,并用氨基酸自动分析仪、双波长比色法、放射性配基结合法分别测定了脑中游离氨基酸含量、一氧化氮合酶(NOS)活性和海马N-甲基-D-天冬氨酸受体(NMDA-R)的数目及亲和力。结果显示补充Gln 后,大鼠的主动回避反应率显著增加,被动逃避时间缩短,脑中Glu、天门冬氨酸Gln、精氨酸含量显著增高,NOS活性和海马NMDA-R数目亦增加,而补充Glu 组未观察到上述作用。结果提示:Gln 对大鼠的学习记忆具有促进作用,而Glu 则无此作用,推测其机理可能与脑中兴奋性氨基酸含量、气体信使分子NO的参与及海马NMDA-R的改变有关     

PAS一Na对染锰雄性大鼠生殖毒性影响的研究

给大鼠染锰（ＭｎｃＬ＿２·４Ｈ＿２Ｏ，１５ｍｇ／ｋｇ／ｄ，ｉｐ）４、８周，再用ＰＡＳ一Ｎａ（１２０ｍｇ／ｋｇ／ｄ，ｉｐ）治疗３周后，通过光、电镜观察ＰＡＳ一Ｎａ对染锰雄性大鼠生殖毒性的影响。结果表明，染锰４、８周大鼠睾丸的支持细胞中溶酶体增加。此外，在染锰８周大鼠的睾丸中还观察到各级精细胞减少，细胞核呈不规则性改变。在光镜下也观察到曲细精管变性的表现，受损严重者，仅残存支持细胞和少量的精细胞，管腔中的精子消失。附睾尾的精子密度明显降低，精子畸形率升高。经ＰＡＳ一Ｎａ治疗后，睾丸病理组织学的表现恢复正常，精子数上升到正常水平，精子畸形率降低。提示ＰＡＳ一Ｎａ可拮抗锰的雄性生殖毒性。     

氧化应激在间歇低氧诱导大鼠海马损伤中作用的研究

目的 探讨氧化应激在间歇低氧（IH）诱导大鼠海马损伤中的作用.方法 30只成年雄性Sprague-Dawley 大鼠随机分成对照组（CON组）、间歇低氧组（IH组）、Melatonin组（MEL组）,每组10只.采用化学比色法测定大鼠海马组织丙二醛（MDA）、超氧化物歧化酶（SOD）水平,并采取RT-PCR方法检测海马组织中Cu/Zn SOD、GPx、CAT的mRNA水平.结果 （1）在IH组中,MDA的水平为（1.68±0.23）μmol/g protein,均高于对照组和MEL组的（1.25±0.14）μmol/g protein和（1.35±0.18）μmol/g protein（P＜0.05或P＜0.01）;（2）在IH组中,SOD的活性、Cu/ZnSOD、GPx、CAT的mRNA表达水平分别为（43.01±4.96）103NU/g protein、0.25±0.02、0.34±0.09、0.38±0.03,均低于对照组和MEL组的（61.12±5.68）103NU/g protein和（55.98±4.65）103NU/g protein、0.48±0.06和0.43±0.08、0.55±0.07和0.54±0.05、0.57±0.04和0.53±0.07（P＜0.05,P＜0.01）.结论 间歇低氧可通过氧化应激导致大鼠海马损伤,MEL能抑制间歇缺氧导致的氧化应激,从而对间歇低氧大鼠海马损伤具有保护作用.