维生素E对慢性镉中毒小鼠黑质神经元的保护作用

75只三月龄雄性昆明种小鼠 ,随机分为三组 :正常对照组、镉 (Cadmium,Cd)中毒组及维生素 E加镉组。通过光镜、透射电镜及细胞形态计量方法定性定量研究三组小鼠黑质神经元的细微结构。研究结果表明 ,正常对照组小鼠黑质神经元结构正常 ;镉中毒组小鼠中脑黑质受损 ,黑质区神经元数量明显减少 ,部分神经元变性、坏死 ,异染色质增多边聚 ,核膜断裂 ,核周质内细胞器明显减少 ,此外有多处较大的软化灶形成 ,并有广泛的淋巴细胞浸润 ,围绕在血管周围形成血管套 ;维生素 E加镉组小鼠黑质区神经元轻微受损 ,结构接近正常组 ,与镉中毒组比较有明显…     

维生素E对慢性染镉肝细胞凋亡的拮抗作用

目的　探讨维生素E(vitaminE ,VE)对慢性染镉肝细胞凋亡的拮抗作用。方法　健康昆明种小鼠 75只 ,体重 2 8g～ 32g ,随机分 3组 :染镉组 (Cdcl2 2mg·kg-1,皮下注射 ,每周 2次 ,共 3个月 )、VE +镉组 (染镉同时给VE 10mg·kg-1·d-1,灌胃 )、正常对照组 (注射等量生理盐水 )。采用免疫组化细胞凋亡染色 (Tunel法 )结合形态计量分析 ,观察 3组小鼠肝细胞凋亡的形态和数量改变。结果　 (1)染镉组小鼠肝细胞可见较多的细胞凋亡 ,VE +镉组肝细胞凋亡数量较少 ;细胞计数表明 ,VE +镉组细胞凋亡数量比染镉组明显减少 (P <0 0 1) ,而与正常对照组相比无显著性差异 (P >0 0 5 )。 (2 )凋亡肝细胞主要有以下形态特点 :①细胞胞体变小 ;②细胞核核仁消失 ,染色质浓缩边集于核膜下 ,核呈环状 ,晚期核固缩、变小 ,深染、致密度高。形态计量分析表明 ,凋亡肝细胞核的平均截面积、平均表面积、平均截面周长、体积密度等形态参数值均较正常肝细胞核明显减小 ,有显著性差异 (P <0 0 1) ;③核碎裂 ,形成凋亡小体。结论　VE对镉所致的肝细胞凋亡有抑制作用。     

维生素E对镉中毒小鼠睾丸生精细胞保护作用的形态学研究

目的探讨维生素E(VitaminE,VE)对慢性镉中毒小鼠睾丸生精细胞损伤的保护作用。方法3月龄昆明种雄性小鼠60只,随机分3组:镉组(每次CdCl22mg/kg,皮下注射,每周2次,共3个月),VE组(染镉同时给VEl0mg·kg-1·d-1,灌胃)和正常对照组(注射等量生理盐水),用光镜、电镜观察生精细胞形态变化,并对精原细胞和精子的超微结构进行立体定量分析。结果(1)与正常对照组比较,镉组小鼠睾丸均受损,根据受损程度可分为轻、中、重3型;精原细胞胞核和精子头内细胞核的平均截面积、平均体积和平均表面积等形态参数值均显著缩小(P<0.05);(2)VE组:大部分小鼠睾丸的形态结构接近正常,仅少部分小鼠的睾丸受到轻、中型损伤;精原细胞胞核和精子头内细胞核的平均截面积、平均体积和平均表面积等形态参数值与正常对照组的相应值接近,无显著性差异(P>0.05)。结论VE对镉引起的小鼠生精细胞形态的损伤有一定保护作用。     

单唾液酸神经节苷脂(GM_1)对经MPTP破坏的小鼠黑质纹状体多巴胺神经元的保护作用

将1一甲基一4苯基一1.2.3.6四氢吡啶(MPTP)经腹腔注入小鼠,连续注射6天,一组动物注射后次日处死;另一组动物存活二周后处死;第三组动物在给予1—甲基一4苯基一1.2.3.6四氢吡啶的同时,经腹膜腔注射神经节苷脂持续三周;第四组为对照组.各组动物脑用酪氨酸羟化酶抗体进行免疫组化观察.结果发现1一甲基一4苯基一1.2.3.6四氢吡啶连续注射后次日处死的动物黑质致密部酪氨酸羟化酶阳性神经元数量明显减少,纹状体中酪氨酸羟化酶阳性终末亦明显稀疏.损害后存活二周组,不论黑质或纹状体的损害均略轻.单唾液酸神经节苷脂组黑质致密部酪氨酸羟化酶阳性神经元及纹状体中酪氨酸羟化酶阳性终末均较上两组明显增多.实验表明,单唾液酸神经节苷脂对经1一甲基一4苯基一1.2.3.6四氢吡啶破坏后的小鼠黑质纹状体系多巴胺神经元有保护作用,防止多巴胺神经元因损害引起的继发性退变.     

用小鼠和犬检测维生素C对缺氧复合NaCN中毒的干预作用

目的探讨维生素C对缺氧复合氰化钠（NaCN）中毒的干预效果。方法实验分两部分,NaCN毒性测定采用小鼠为实验对象,自制小型缺氧箱,用N2／O2混合气体置换法制备缺氧模型。在常氧环境和缺氧环境下分别给予腹腔注射0、6．0、7．5、9．0、10．5、12．0mg／kg剂量的NaCN,维生素C干预组在注射NaCN后立刻注射维生素C300mg／kg,观察24h并记录动物死亡数。心脏功能检测以犬为对象,动物麻醉后行气管插管术和左心室导管插管术,缺氧组经气管插管吸入N2／O2混合气体。经皮下注射给药NaCN3mg／kg,维生素C干预组同时给予维生素C300mg／kg,记录心电PPd、QRSd及左心室压力的变化情况。结果在6．0-12．0mg／kg剂量范围内,NaCN中毒小鼠的死亡率随着给药剂量增大而增加,缺氧环境比常氧环境下的死亡率高。经维生素C干预,常氧环境和缺氧环境下NaCN中毒的死亡率均有所下降。3．0mg／kgNaCN腹腔注射后,常氧和缺氧犬心电PPd和QRSd时限均显著缩短,左心室压力明显下降。NaCN中毒后立刻注射维生素C,可有效缓解上述指标的变化。结论维生素C对缺氧复合NaCN中毒的毒性及其对心脏功能的影响具有一定的干预作用。     

慢性镉中毒小鼠肾脏的超微结构观察

透射电镜下观察10只慢性镉中毒小鼠肾脏的超微结构变化，结果表明肾小体和近曲小管上皮细胞的超微结构均受损伤，肾小体，毛细血管内皮细胞肿胀，增厚，血管系膜增生，血管球基膜增厚或分裂成层，基膜和内皮细胞之间或基膜的分裂之间有电子致密物沉积，近曲小管上皮细胞，胞核变形，固缩，线粒体肿胀，嵴断裂，脱落，细胞游离面微绒毛肿胀，变形，排列紊乱，细胞基底面质膜内褶减少或消失，这些超微结构的改变与某些类型肾小球肾炎的病理特征相似。     

Fluoro-Jade C染色方法显示神经毒物MPTP和红藻氨酸致小鼠中脑黑质神经元的变性死亡

为探讨Fluoro-JadeC荧光染色检测神经毒物MPTP和红藻氨酸(KA)损伤致中脑黑质神经元变性死亡的方法,本研究采用小鼠腹腔注射MPTP或黑质定位注射KA制备黑质损伤模型,然后进行Fluoro-JadeC染色标记和计数分析黑质内变性死亡神经元。结果显示:Fluoro-JadeC(FJC)染色可清晰地显示MPTP或KA致小鼠黑质损伤后出现的变性神经元,包括变性神经元的细胞胞体和突起。在中脑组织切片上,MPTP模型与KA模型黑质致密部内有许多FJC染色阳性的变性神经元,而对照组动物黑质内未见FJC染色阳性的变性神经元分布。本研究结果表明:FJC方法能够很好地显示MPTP和KA动物模型黑质内神经元的变性死亡,具备很高的对比度和分辨率,是一种特异性标记黑质变性神经元树突、轴突和胞体的优良染色方法。     

MPTP对小鼠黑质与纹状体KIF基因表达的影响

目的: 揭示1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)对C57BL小鼠黑质与纹状体神经元驱动蛋白超家族(KIF)基因表达的影响。方法: 腹腔注射MPTP建立小鼠帕金森病动物模型,通过RT-PCR方法检测KIF1A、KIF2、KIF3A、KIF4与KIF5A基因的表达。结果: 在黑质中,MPTP造成KIF基因表达的普遍下降,只有KIF2基因表达无明显变化。在纹状体中则有所不同,KIF1A、KIF3A与KIF4基因表达上升,而KIF2与KIF5A表达的变化与在黑质中相似。结论: MPTP造成的神经黑质多巴胺能神经元丧失很可能与KIF基因表达的降低有关。     

镉对大鼠附睾的损伤及锌和维生素E的保护作用

用透射电镜结合脂质过氧化物（ＬＰＯ）含量分析法，观察小剂量氯化镉（２ｍｇ／ｋｇ体重）腹腔内注射后１０ｍｉｎ至６０ｄ大鼠附睾头部的损伤改变及锌和维生素Ｅ（ＶＥ）的保护作用。结果表明：注射镉后３０ｍｉｎ，主细胞已出现超微结构改变；３￣７ｄ时主细胞和管周组织及毛细血管退变加重；１５￣３０ｄ时退变有所减轻；６０ｄ时主细胞有恢复趋势而管周组织增厚。镉注射后附睾管周组织内碱性磷酸酶（ＡＬＰａｓｅ）反应产物明显     

体外循环对血小板的影响及维生素C对其的保护作用

为观察心脏直视手术中体外循环对血小板的损害作用及维生素Ｃ其的保护作用，将１７例未合并肺动脉高压的室间隔缺损进行心脏直视手术的病人随机分为对照组（１０例）和维生素Ｃ组（７例），应用透射电镜观察体外循环过程中血小板的超微结构的变化，并对维生素Ｃ组应用维生素Ｃ进行保护。结果表明：体外循环期间，对照组的血小板聚集堆逐渐增多，以转流３０ｍｉｎ时最为明显，同时崩解型血小板也增多；而维生素Ｃ组血小板数量下降程度、血小板聚集堆及崩解型血小板增加程度远较对照组小。结果提示：体外循环对血小板超微结构形态有明显损害，而维生素Ｃ对其有明确的保护作用。     

The role of the substantia nigra in a striatally-evoked motor response in the rat: effects of intranigral drugs and lesions

Turning of the head towards the contralateral side was induced in the conscious unrestrained rat by electrical stimulation of the neostriatum through permanent indwelling electrodes. The importance of the substantia nigra in mediating this response was investigated using electrolytic and kainic acid lesions. Contralateral head-turning was attenuated by small electrolytic lesions of the substantia nigra on the stimulated side and abolished by large electrolytic lesions that destroyed the entire nucleus. The injection of kainic acid into the substantia nigra caused persistent circling behaviour but did not modify the head-turn response to striatal stimulation; these injections destroyed some of the neurons in the pars compacta but the majority of neurons in the pars reticulata were undamaged. Drugs that alter the function of nigral neurotransmitters were injected through an indwelling cannula in the zona reticulata. Interference with the function of γ-aminobutyrate in the nigra produced small changes in the latency of the motor response. However the following drugs did not modify the response: substance P, nicotine, atropine, apomorphine, glutamic acid diethylester, glycine, strychnine, met-enkephalin and 5-methoxy-N,N-dimethyltryptamine.It is concluded that descending projections from the basal ganglia which pass through or very close to the nigra, probably without forming synapses in the pars reticulata, may be important for the mediation of the striatally-evoked response.     

Behavioral and electrophysiological changes following microinjections of colchicine into the substantia nigra.

Male Sprague-Dawley rats received bilateral microinjections of colchicine (2 or 4 μg in 1 μl) into the substantia nigra. During the first 2 days the animals were hyperactive, intense gnawing and chewing were observed, and food intake was significantly increased. During the next 3 or 4 days, activity, food and water intakes and body weight gain were markedly reduced; the behavior was similar to that previously observed following damage to the substantia nigra and nigrostriatal pathway from 6-hydroxydopamine or electrolytic lesions. This period of hypophagia and hypodipsia was followed by a rebound increase in food and water intake for several days until body weight returned to normal levels. Field potentials recorded from the caudate nucleus in response to electrical stimulation of the substantia nigra were reduced in amplitude during the first 4 days following microinjections of colchicine into the substantia nigra and recovered by Day 7.These reversible behavioral effects of microinjections of colchicine into the substantia nigra confirm the importance of the nigrostriatal pathway in motor and ingestive behaviors.     

Prenatal LPS increases inflammation in the substantia nigra of Gdnf heterozygous mice

Prenatal systemic inflammation has been implicated in neurological diseases, but optimal animal models have not been developed. We investigated whether a partial genetic deletion of glial cell line-derived neurotrophic factor (Gdnf(+/-)) increased vulnerability of dopamine (DA) neurons to prenatal lipopolysaccharide (LPS). LPS [0.01 mg/kg intraperitoneal (i.p.)] or saline was administered to wild-type (WT) or Gdnf(+/-) pregnant mice on gestational day 9.5. Male offspring were examined at 3 weeks, 3 and 12 months of age. There was a progressive degeneration of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) with age in Gdnf(+/-) but not in WT mice, with no observed effects on locus coeruleus (LC) noradrenergic neurons or DA neurons of the ventral tegmental area. Inflammatory markers were elevated in SN of LPS treated offspring, with exacerbation in Gdnf(+/-) mice. Intracellular accumulation of α-synuclein (α-syn) immunoreactivity in DA neurons of SN was observed in all groups of Gdnf(+/-) and in WT mice with prenatal LPS, with altered distribution between pars reticulata (pr) and pars compacta (pc). The findings suggest that prenatal LPS leads to accelerated neuropathology in the SN with age, and that a partial loss of GDNF exacerbates these effects, providing a novel model for age-related neuropathology of the nigrostriatal DA system.     

Investigation of the connection between the substantia nigra and the medullary reticular formation in the rat

Unfixed, slide-mounted tissue sections from the rat forebrain have been incubated in the presence of 20 and 100 nM [3H]kainic acid ([3H]KA). For the last 2 min of incubation, 10 micrometers unlabelled KA was added to displace [3H]KA from binding sites with high on-off rate. Washed and dried slices were exposed on [3H]Ultrofilm for 178 days. Our results confirm the high density of KA receptors in the terminal field of the hippocampal mossy fibre system which is shown to be due to receptors with slow dissociation rate. Furthermore, the concentration dependency of the specific labelling, as quantified by microdensitometry, allows some suggestions concerning the local binding affinities involved.     

Evidence for functional interactions of morphine in substantia nigra and striatum in relation to muscular rigidity in rats

Systemic administration of morphine (15 mg/kg i.p.) induced muscular rigidity in rats, which was recorded from the gastrocnemius-soleus muscle as tonic activity in the electromyogram. Administration of morphine (5 or 10 μg) into the pars compacta of the substantia nigra antagonized the rigidity in a dose-dependent manner, whereas administration of morphine at a dose of 5 μg into the pars reticulata of the substantia nigra enhanced the tonic EMG activity. When morphine and naloxone were co-administered intranigrally, the tonic EMG activity was not affected.     

帕金森病大鼠未注射侧纹状体和黑质酪氨酸羟化酶的表达

目的:观察不同病程偏侧帕金森病(PD)大鼠未注射侧纹状体和黑质酪氨酸羟化酶(TH)的表达.方法:6-羟基多巴胺(6-OHDA)右侧前脑内侧束立体定位注射1周,阿朴吗啡旋转实验筛选PD模型大鼠,随机分为2、4周和6周模型组,另设正常对照组.行嘴侧纹状体节段和黑质节段连续冠状石蜡切片,采用焦油紫染色定位,以TH抗体免疫组织化学阳性显示多巴胺(DA)能神经元胞体和纤维.结果:正常对照组和2周模型组大鼠左侧纹状体有较强的TH表达,而4周和6周模型组左侧纹状体的TH表达强度较上述两组降低,4周和6周模型组之间无差异.4组大鼠左侧黑质TH表达阳性细胞数无差异.正常对照组、2周和4周模型组左侧黑质有较强的TH表达,3组的表达强度无差异,而6周模型组左侧黑质的TH表达强度较上述3组均降低.结论:6-OHDA单侧注射制备的PD模型大鼠,注射侧的长期病变致未注射侧纹状体和黑质TH的表达减弱.     

Tolbutamide reverses membrane hyperpolarisation induced by activation of D2 receptors and GABAB receptors in isolated substantia nigra neurones

A high density of binding sites for sulphonylureas is found in the substantia nigra. These binding sites may be linked to ATP-regulated K-channels (K-ATP channels) as sulphonylureas selectively inhibit these channels in pancreatic ß-cells. We have studied the effect of the sulphonylurea tolbutamide on the electrical properties of freshly isolated neurones from guinea-pig substantia nigra, using the perforated patch technique. In spontaneously firing cells, both the D₂ agonist quinpirole and the GABA_B agonist baclofen abolished firing, hyperpolarised the cell and increased the whole-cell conductance. Tolbutamide reversed all three effects, but was without effect in the absence of quinpirole or baclofen. We suggest that D₂ and GABA_B receptors activate a K-channel that is blocked by tolbutamide.     

别孕烯醇酮对APPswe/PSEN1小鼠黑质多巴胺能神经元的影响

目的 评估别孕烯醇酮（APα）对阿尔茨海默病（AD）小鼠黑质（SN）酪氨酸羟化酶（TH）神经元数目的影响。方法 31只4月龄雄性小鼠采用免疫荧光染色观察和计算各种免疫阳性细胞的数目。结果 双转基因AD小鼠（2×TgAD）APα水平和TH神经元数目均明显减少,且出现在β 淀粉样斑块形成之前。给予APα处理可预防2×TgAD小鼠SN总神经元、TH神经元和TH/5 溴脱氧尿嘧啶核苷（BrdU）神经元数目的下降,但对纹状体TH神经纤维吸光度下降无影响。此外,APα能增加2×TgAD小鼠新生成熟神经元的数目,但对新生胶质细胞数目无影响。结论 2×TgAD小鼠体内低水平APα与多巴胺能神经元下降相关,外源性APα能够通过增加新生TH神经元的形成来恢复2×TgAD小鼠TH神经元的下降。     

大鼠黑质胆碱能神经元形态学的增龄变化

目的：探讨大鼠中脑黑质胆碱能神经元的增龄变化规律。方’法：SD大鼠分为1～2月龄、3～4月龄、11～12月龄、≥24月龄4组,常规石蜡中脑黑质连续冠状切片,HE染色、尼氏染色、胆碱乙酰基转移酶(ChAT)免疫组织化学染色,图像分析仪测量ChAT免疫阳性产物的光密度和ChAT免疫反应阳性神经元的多种参数。结果：随着年龄增长,大鼠中脑黑质神经元数量减少,ChAT免疫反应阳性神经元平均光密度减少,ChAT免疫反应阳性神经元多种形态学参数均减少,呈增龄衰老性变化。结论：黑质胆碱能神经元随年龄增长而出现的衰老性变化,可能是黑质病变的原因之一。