帕金森病大鼠胃肠功能障碍的机制

目的 探讨6-羟基多巴胺(6-OHDA)诱导的SD大鼠帕金森病(PD)模型胃肠功能障碍的发生机制.方法 60只SD大鼠随机分为6-OHDA组和对照组;以6-OHDA诱导制备PD大鼠模型.4周后收集大鼠1h粪便排出量,计算粪便含水量,测定餐后2 h大鼠胃内固体食物残留率.采用免疫组化法检测黑质酪氨酸羟化酶(TH)、胃肠神经丛α-突触核蛋白(α-syn)、神经元型一氧化氮合酶(nNOS)的表达;应用逆转录(RT)-PCR方法检测胃、结肠组织nNOS mRNA的表达.结果 与对照组相比,6-OHDA组大鼠1 h粪便排出量及含水量明显降低,胃内固体食物残留率明显增加(均P<0.01);损伤侧黑质TH阳性细胞明显减少(P<0.01);胃肠肌间神经丛α-syn表达明显升高,nNOS表达明显降低(均P<0.01);胃肠组织nNOS mRNA表达明显降低(均P<0.01).结论 PD大鼠胃肠功能障碍可能与胃肠神经系统nNOS水平降低有关.     

帕金森病大鼠模型神经元型一氧化氮合酶(nNOS)阳性神经元的实验研究

目的 观察研究帕金森病(PD)大鼠模型纹状体神经元型一氧化氮合酶(nNOS)阳性神经元，探讨一氧化氮(NO)在PD发病机制中所起作用。方法 应用立体定向技术建立6-OHDA毁损的大鼠PD模型，通过多巴胺受体激动剂阿扑吗啡(APO)测试大鼠旋转行为，免疫组化方法观察黑质酪氨酸羟化酶(TH)阳性神经元和纹状体nNOS阳性神经元的变化。结果 大鼠6-OHDA损毁侧黑质TH阳性神经元数目较对侧明显减少，双侧纹状体nNOS阳性神经元数目无显著差异。结论 6-OHDA对TH阳性神经元有损伤作用，而NOS阳性神经元对其具有抵抗作用。NO可能参与了PD发病机制。     

一氧化氮和一氧化氮合酶在大鼠局灶性脑缺血中的表达特点

目的建立脑缺血SD大鼠模型,探讨一氧化氮(NO)和一氧化氮合酶(NOS)在脑缺血模型中的表达特点。方法应用线栓法制作大脑中动脉阻塞(MCAO)局灶性脑缺血模型,根据缺血不同时间分为8组,设立假手术组和正常对照组,每组各有6只大鼠。应用硝酸还原酶法测定脑组织NO的含量,流式细胞术(FCM)定量检测硝基酪氨酸(NT)表达,化学比色法测定脑组织NOS的活性,免疫组织化学方法定位检测eNOS、nNOS和iNOS表达位置,逆转录反应系统(RT-PCR)半定量分析eNOS、nNOS和iNOS的 mRNA在脑缺血区域的表达。结果神经功能缺失评分发现缺血时间越长,神经功能缺失越明显;脑组织中NO含量与缺血时间正相关;缺血1h后NT阳性细胞百分比开始明显升高(9.50%);缺血0.5h时NOS的活性开始升高,缺血3d达到高峰[0.94nmol/(g.min)];免疫组织化学提示eNOS在神经细胞和血管内皮细胞胞浆均有表达,nNOS和iNOS抗体主要在神经细胞胞浆中表达;RT-PCR半定量分析在缺血早期(0.5h~6h),随着缺血时间延长,eNOS和nNOS表达增加,iNOS未见表达或低表达;缺血中晚期(6h~5d),iNOS高表达,并与缺血时间呈正相关,eNOS和nNOS表达明显减少。结论脑缺血时间延长,NOS的活性升高,NO在体内特异性代谢产物NT量增加,神经功能缺失越明显;NOS在缺血早期以eNOS和nNOS为主,在缺血晚期以iNOS为主。     

偏侧帕金森病猴模型黑质和纹状体一氧化氮合酶表达的变化

目的探讨偏侧帕金森病（PD）猴模型黑质和纹状体一氧化氮合酶（NOS）表达的变化。方法对3只恒河猴经单侧颈内动脉注射1-甲基4-苯基1,2,3,6-四氢吡啶（MPTP）制备成偏侧PD猴模型后,应用还原型尼克酰胺腺嘌呤二核苷酸-黄递酶（NADPH．d）组化染色方法观察偏侧PD猴黑质和纹状体NOS阳性神经元表达的变化,并与正常猴比较。结果偏侧PD猴MPTP毁损侧的黑质和纹状体的NOS阳性神经元数目较毁损对侧和正常猴明显增加（均P〈0．01）,毁损对侧的黑质和纹状体NOS阳性神经元数目与正常猴比较差异无统计学意义。结论偏侧PD猴黑质和纹状体NOS阳性神经元增多,由此引起一氧化氮（NO）合成和释放增多,可能对黑质和纹状体神经元的变性和死亡起重要作用。     

慢性间断性缺氧诱导一氧化氮合酶表达的研究

目的:建立大鼠缺氧模型,检测神经元型一氧化氮合酶(nNOS)及诱导型一氧化氮合酶(iNOS)的表达情况。方法:1.建立缺氧模型:将SD大鼠置于常压低氧舱中,充入氮气调节氧浓度至所需氧浓度。2.动物分组:(1)急性缺氧组:在低氧舱中缺氧1.5小时。(2)慢性间断性缺氧组:每日在低氧舱中6小时。每周缺氧6天,共缺氧28天。3.采用免疫组化法检测nNOS和iNOS的表达。4.统计学分析检验。结果:急性缺氧后,iNOS、nNOS阳性神经元增加;慢性缺氧后,iNOS、nNOS阳性神经元仍持续增多,慢性缺氧时增加iNOS-IR细胞远远多于nNOS-IR细胞。结论:我们的研究表明缺氧可引起iNOS、nNOS阳性神经元增加,NOS亚型表达时间的不同说明其脑损伤具有阶段性。     

NOS在棕色田鼠胃肠道各段肌间神经丛分布的比较

目的:解释棕色田鼠(Microtus mandarinus)消化道对其生活史特征的适应性调节机制.方法:用NAD-PH-黄递酶组织化学法对NOS在棕色田鼠胃肠肌间神经丛的分布进行比较研究.结果:棕色田鼠胃肠肌间神经丛NOS阳性神经元形态各异,大小悬殊数倍;神经节和阳性神经纤维构成网络结构,阳性神经元可呈"串珠"状和"U"形排列.NOS阳性神经元分布密度在胃肠道各段差异较大:结肠密度最高,回肠次之,胃和盲肠比回肠低.比十二指肠和空肠高.结论:棕色田鼠NOS阳性神经元在胃肠道各节段肌间神经丛的分布特点可能是与其食性和生理机能相适应的.     

NOS在棕色田鼠胃肠道各段肌间神经丛分布的比较

目的：解释棕色田鼠(Microtus mandarinus)消化道对其生活史特征的适应性调节机制。方法：用NAD-PH-黄递酶组织化学法对NOS在棕色田鼠胃肠肌间神经丛的分布进行比较研究。结果：棕色田鼠胃肠肌间神经丛NOS阳性神经元形态各异，大小悬殊数倍；神经节和阳性神经纤维构成网络结构，阳性神经元可呈“串珠”状和“U”形排列。NOS阳性神经元分布密度在胃肠道各段差异较大：结肠密度最高，回肠次之，胃和盲肠比回肠低，比十二指肠和空肠高。结论：棕色田鼠NOS阳性神经元在胃肠道各节段肌间神经丛的分布特点可能是与其食性和生理机能相适应的。     

尼古丁对帕金森病小鼠脑组织一氧化氮合酶活性的影响

帕金森病 (ＰＤ)的主要病理变化为黑质纹状体多巴胺(ＤＡ)能神经元变性 ,其病因及发病机制尚不明确。有研究发现 ,应用甲基 苯基 四氢吡啶 (ＭＰＴＰ)制作的ＰＤ小鼠脑组织神经元型一氧化氮合酶 (ｎＮＯＳ)活性增高 ,认为一氧化氮(ＮＯ)参与了ＭＰＴＰ的神经毒作用。某些流行病学及生物学资料表明 ,吸烟对ＰＤ的发病具有保护作用 ,但其作用机制尚不清楚。本实验采用雄性Ｃ5 7ＢＬ小鼠腹腔注射ＭＰＴＰ建立小鼠ＰＤ模型 ,观察尼古丁对ＰＤ小鼠脑组织ｎＮＯＳ活性的影响 ,以探讨尼古丁对ＭＰＴＰ神经毒性的可能保护机制。材料和方法 :选用 8周…     

神经元型一氧化氮合酶在血管性痴呆大鼠海马中的表达

目的 探讨神经元型一氧化氮合酶(nNOS)在血管性痴呆(VD)大鼠海马中的表达。方法 将60只大鼠随机分为：对照组、VD12h组、VD1d组、VD3d组、VD7d组。采用反复夹闭双侧颈总动脉方法建立VD大鼠模型，用HE染色观察各组大鼠海马CA1区神经元的数目；应用免疫组化染色和Western印迹方法检测nNOS在大鼠海马中的表达。结果 VD12h组、VD1d组、VD3d组、VD7d组大鼠海马CA1区神经元数均明显下降。nNOS在对照组大鼠海马CA1区中弱表达．在VD12h组表达增强．VD1d组进一步增强，VD3d和7d组表达逐渐减弱。结论 nNOS可能参与缺血早期海马神经元的损害，是VD的发病机制之一。     

脑缺血早期大脑皮质区神经元内一氧化氮合酶活性的变化

建立大鼠ＭＣＡＯ局灶脑缺血模型,利用ＮＡＤＰＨ－ｄ组织化学方法检测脑缺血早期大脑皮质缺血区神经元内一氧化氮合酶活性的变化。结果显示脑缺血早期３０ｍｉｎ神经元内一氧化氮合酶活性开始至高峰,随后下降,脑缺血后６０ｍｉｎ,降至正常。     

NADPH-diaphorase/nitric oxide synthase containing neurons in normal and Parkinson's disease putamen

Summary Nitric oxide (NO) is thought to be involved in neurodegenerative processes. Concerning Parkinson's disease (PD) it remains to be elucidated, if NO contributes to pathological alterations in the striatum. The present study evaluates the post-mortem putamen of PD patients and control subjects for distribution patterns of NO-synthase containing neurons, using the NADPH-diaphorase technique. The ratio of positively stained neurons and the total number of cells (control: 1,120±69 per mm², n=5; PD: 575±164mm², n=5) shows striking differences between controls and PD patients. Our findings give reason to conclude that NADPH-diaphorase positive structures may have pathogenetic importance in degenerative processes in PD putamen.     

Aging of the myenteric plexus: neuronal loss is specific to cholinergic neurons

Neuron loss occurs in the myenteric plexus of the aged rat. The myenteric plexus is composed of two mutually exclusive neuronal subpopulations expressing, respectively, nitrergic and cholinergic phenotypes. The goal of the present study, therefore, was to determine if neuron loss is specific to one phenotype, or occurs in both. Ad libitum fed virgin male Fischer 344 rats of 3 and 24 months of age were used in each of two neuronal staining protocols (n=10/age/neuron stain). The stomach, duodenum, jejunum, ileum, colon, and rectum were prepared as whole mounts and processed with either NADPHd or Cuprolinic Blue to stain, respectively, the nitrergic subpopulation or the entire population of myenteric neurons. Neuron numbers and sizes were determined for each preparation. Neuron counts from 24-month-old rats were corrected for changes in tissue area resulting from growth. There was no age-related loss of NADPHd-positive neurons for any of the regions sampled, whereas significant losses of Cuprolinic Blue-labeled neurons occurred in the small and large intestines of 24-month-old rats. At the two ages, the average neuron sizes were similar in the stomach and small intestine for both stains, but neurons in the large intestine were significantly larger at 24 months. In addition, numerous swollen NADPHd-positive axons were found in the large intestine at 24 months. These findings support the hypothesis that age-related cell loss in the small and large intestines occurs exclusively in the cholinergic subpopulation. It appears, however, from the somatic hypertrophy and the presence of swollen axons that the nitrergic neurons are not completely spared from the effects of age.     

Vasoactive intestinal peptide and nitric oxide promote survival of adult rat myenteric neurons in culture

Several motility disorders originate in the enteric nervous system (ENS). Our knowledge of factors governing survival of the ENS is poor. Changes in the expression of vasoactive intestinal peptide (VIP) and nitric oxide synthase (NOS) in enteric neurons occur after neuronal injury and in intestinal adaptation. The aim of this study was to evaluate whether VIP and nitric oxide (NO) influence survival of cultured, dissociated myenteric neurons. Neuronal survival was evaluated after 0, 4, and 8 days in culture. Influence of VIP and NO on neuronal survival was examined after culturing in the presence of VIP, NO donor, VIP antiserum, or NOS inhibitor. A marked loss of neurons was noted during culturing. VIP and NO significantly promoted neuronal survival. Corroborating this was the finding of an enhanced neuronal cell loss when cultures were grown in the presence of VIP antiserum or NOS inhibitor.     

依达拉奉对帕金森病大鼠模型的神经保护作用及黑质纹状体丙二醛和一氧化氮水平的影响

目的 探讨依达拉奉对帕金森病(PD)大鼠的神经保护作用及黑质纹状体丙二醛(MDA)和一氧化氮(NO)水平的影响.方法 将72只SD大鼠随机分为正常对照组(n=12)、生理盐水对照组(NS组,n=12)、依达拉奉治疗组(ED组,n=48),ED组又分为ED 0.3 mg、1 mg、3 mg及3 mg停药后亚组,每个亚组12只大鼠.在大鼠脑内注入6-羟基多巴胺(6-OHDA)制作PD模型,术后各组大鼠分别相应给予NS 1 ml及ED 0.3 mg/kg、1 mg/kg、3 mg/kg腹腔注射,每天2次,连续14 d.对各组大鼠并进行旋转试验;用免疫组化染色检测黑质酪氨酸羟化酶(TH)阳性细胞数,化学比色法检测黑质纹状体MDA和NO水平.结果 正常对照组大鼠旋转圈数与NS组及ED各亚组比较,差异有统计学意义(均P＜0.01).ED 3 mg及ED 3 mg停药后亚组的旋转圈数显著少于NS组及ED 0.3 mg、1 mg亚组(均P＜0.05).NS组及各ED亚组左侧黑质TH阳性神经元显著少于正常对照组及右侧(均P ＜0.05).ED 3 mg及ED 3 mg停药后亚组左侧黑质TH阳性神经元显著多于NS组和ED 0.3 mg、1 mg亚组(均P＜0.05).与正常对照组比较,NS组和各ED亚组黑质、纹状体NO和MDA水平显著升高(均P＜0.01).ED 3 mg及ED 3 mg停药后亚组黑质、纹状体NO和MDA水平较NS组和ED 0.3 mg、1 mg亚组显著降低(均P＜0.05).结论 依达拉奉对PD大鼠的神经保护作用呈剂量依赖性;其能抑制过氧化反应,降低PD大鼠黑质纹状体的MDA、NO水平.     

Neurochemical coding in the myenteric plexus of the upper gastrointestinal tract of hibernating hamsters

As part of our investigation of the plasticity of autonomic nerves in physiological and pathological conditions, we have examined the effect of hibernation on the neurochemical content of myenteric nerves and nerve cell bodies of the upper gastrointestinal tract of the non-seasonal hibernator, the golden hamster. Age matched hamsters kept at room temperature and those kept at 5°C but failed to hibernate, were used as controls. Possible changes in nerve fibers and nerve cell bodies containing the general neuronal marker, protein gene product 9.5, the peptides, vasoactive intestinal polypeptide, substance P (SP) and calcitonin gene-related peptide (CGRP), the catecholamine synthesizing enzyme tyrosine hydroxylase and the enzyme responsible for synthesizing nitric oxide, nitric oxide synthase, were examined in the oesophagus, proventriculus and proximal and distal stomach of the golden hamsters using immunohistochemical techniques. The results of the present study revealed a significant increase in the number of nerve cell bodies and density of nerve fibers containing SP-immunoreactivity and increased number of CGRP-immunoreactive cell bodies but not the other markers examined in the proximal stomach and proventriculus. In contrast, there was no change in the distribution of any of the neuroactive substances examined in the myenteric plexus of the oesophagus and distal stomach. It is suggested that the change in the environment of the hibernating hamsters perturbs the normal digestive physiology in the proximal stomach and proventriculus that is reflected by the selective changes in SP- and CGRP-containing enteric nerves; these changes may be part of protective reflex mechanisms to the environmental changes resulting from hibernation, where upgrading of nerve cell bodies expessing CGRP and SP has occurred.     

Alpha-synuclein immunopositive aggregates in the myenteric plexus of the aging Fischer 344 rat

Dystrophic axons and terminals are common in the myenteric plexus and smooth muscle of the gastrointestinal (GI) tract of aged rats. In young adult rats, alpha-synuclein in its normal state is abundant throughout the myenteric plexus, making this protein–which is prone to fibrillization–a candidate marker for axonopathies in the aged rat. To determine if aggregation of alpha-synuclein is involved in the formation of age-related enteric neuropathies, we sampled the stomach, small intestine and large intestine of adult, middle-aged, and aged virgin male Fischer 344 rats stained for alpha-synuclein in both its normal and pathological states. Alpha-synuclein-positive dystrophic axons and terminals were present throughout the GI tract of middle-aged and aged rats, with immunohistochemical double labeling demonstrating co-localization within nitric oxide synthase-, calretinin-, calbindin-, or tyrosine hydroxylase-positive markedly swollen neurites. However, other dystrophic neurites positive for each of these four markers were not co-reactive for alpha-synuclein. Similarly, a subpopulation of alpha-synuclein inclusions contained deposits immunostained with an anti-tau phospho-specific Ser²⁶² antibody, but not all of these hyperphosphorylated tau-positive aggregates were co-localized with alpha-synuclein. The presence of heteroplastic and potentially degenerating neural elements and protein aggregates both positive and negative for alpha-synuclein suggests a complex chronological relationship between the onset of degenerative changes and the accumulation of misfolded proteins. Additionally, proteins other than alpha-synuclein appear to be involved in age-related axonopathies. Finally, this study establishes the utility of the aging Fischer 344 rat for the study of synucleopathies and tauopathies in the GI tract.     

Chronic rotenone exposure reproduces Parkinson's disease gastrointestinal neuropathology

Gastrointestinal disorders, particularly severe constipation and delayed gastric emptying, are core symptoms of Parkinson's disease that affect most patients. However, the neuropathological substrate and physiological basis for this dysfunction are poorly defined. To begin to explore these phenomena in laboratory models of PD, rats were treated with either vehicle or rotenone (2.0 mg/kg, i.p.; 5 days/week) for 6-weeks. Myenteric plexus α-synuclein aggregate pathology and neuron loss were assessed 3-days and 6-months after the last rotenone injection. Gastrointestinal motility was assessed at 3-days, 1-month and 6-months after the last rotenone injection. Rotenone treatment caused an acute reduction in α-synuclein-immunoreactivity, but this was followed 6 months later by a robust increase in aggregate pathology and cytoplasmic inclusions that were similar in appearance to enteric Lewy-bodies in idiopathic PD. Rotenone-treated rats also had a moderate but permanent loss of small intestine myenteric neurons and an associated modest slowing of gastrointestinal motility 6-months after treatment. Our results suggest that a circumscribed exposure to an environmental toxicant can cause the delayed appearance of parkinsonian α-synuclein pathology in the enteric nervous system and an associated functional deficit in gastrointestinal motility. The rotenone model may therefore, provide a means to investigate pathogenic mechanisms and to test new therapeutic interventions into gastrointestinal dysfunction in PD.     

神经源型一氧化氮合酶C276T基因多态性与抑郁症相关分析

目的测定抑郁症患者抗抑郁剂治疗前后血浆一氧化氮（NO）水平变化,旨在探讨神经源型一氧化氮合酶（nNOS）基因C276T多态性与血浆NO浓度及抑郁症发病相关性。方法采用硝酸盐还原酶法测定正常对照组及抑郁症患者治疗前后血浆NO水平;全部受试者取全血标本提取基因组DNA,并采用PCR-RFLP方法对nNOS基因C276T多态性进行基因分型。结果患者组疗前血浆NO水平为（76.8±31.6）μmol/L显著高于疗后[（66.9±25.7）μmol/L,P=0.044]及正常对照组[（64.2±33.3）μmol/L,P=0.02],两组疗后血浆NO水平相比差异无显著性（P=0.588）;根据PCR-RFLP结果,nNOS基因可见两种等位基因条带C、T,组成三种基因型CC、CT、TT,两组等位基因及基因型分布频率差异无显著性（均P〉0.05）,且携带不同基因型者之间血浆NO水平差异亦无显著性（均P〉0.05）。结论血浆NO浓度增高可能是抑郁症发病的影响因素;nNOS基因C276T多态性可能不直接影响血浆NO浓度,也不是抑郁症发病的主要基因因素。     

Neuromuscular changes in a rat model of colitis

Intracolonic administration of Trichinella spiralis larvae in rats causes colitis with features similar to ulcerative colitis, notably with inflammation predominantly limited to the colonic mucosa. Our aim was to characterize the functional and neurochemical changes occurring within the myenteric (MP) and submucosal plexuses (SMP) during T. spiralis-induced colitis. Infected rats had decreased body weight, altered stool consistency and elevated myeloperoxidase activity, 6 and 14 days post-infection (PI). Responses to acetylcholine and KCl in circular muscle strips were reduced in infected tissues, demonstrating an impairment of contractility. In addition, there was a decrease in spontaneous motor activity and reduced sensitivity to the nitric oxide synthase (NOS) inhibitor L-NOArg, corresponding with a significant reduction in NOS immunoreactive neurons in the MP of infected animals. T. spiralis did not alter the total number of myenteric or submucosal neurons. Substance P innervation of submucosal blood vessels was reduced after infection, as were submucosal calretinin and calbindin immunoreactive neurons. No changes in choline acetyltransferase and calcitonin gene-related peptide immunoreactivity were observed. T. spiralis-induced colitis causes profound neuromuscular adaptations. The reduction in NOS neurons appears to underlie changes in motility.