莫诺苷对大鼠局灶性脑缺血再灌注损伤神经功能的影响

目的观察中药山茱萸的有效成分莫诺苷对大鼠局灶性脑缺血再灌注后神经功能的影响。方法Wistar雄性大鼠随机分为假手术组、模型组、莫诺苷小剂量组（30 mg/kg）、莫诺苷中剂量组（90 mg/kg）、莫诺苷大剂量组（270 mg/kg）、维生素E（VE）（35 mg/kg）,采用线栓法制作大鼠局灶性脑缺血再灌注模型,缺血30 min后再灌注3 d,应用Zea Longa法、爬网格、平行木、吊绳、Ludmila Belayev 12分评分法,观察莫诺苷对神经功能缺损的改善作用。结果与模型组比较,莫诺苷给药组（小、中、大剂量）Zea Longa法评分均差异极显著（P〈0.01）;与模型组比较,莫诺苷给药组（小、中、大剂量）吊绳法评分均差异极显著（P〈0.01）;Ludmila Belayev 12分评分法评分与模型组比较,莫诺苷大剂量组差异极显著（P〈0.001）,中剂量组差异极显著（P〈0.01）。结论莫诺苷对局灶性脑缺血再灌注模型大鼠有改善行为学评分的作用。     

大鼠半乳糖性白内障动物模型制备方法的改良及其机制

目的改良大鼠半乳糖性白内障动物模型制备方法 ,比较改良前后两种方法各自的特点及其机制。方法 60只体重（180±10）g的雄性成年SD大鼠随机分为空白对照组（C）、半乳糖性白内障组1（G1）和半乳糖性白内障组2（G2）。G1组腹腔注射50%半乳糖溶液20mL/（kg·d）,连续30d;G2组第1周、第2周分别腹腔注射50%半乳糖溶液10、15mL/（kg·d）,第3周开始增至20mL/（kg·d）,直至第30d。应用裂隙灯观察晶体混浊情况,按大鼠晶状体混浊度评分标准进行分级和记录,并分别观察和比较不同制备方法的成模时间、模型成功率、模型死亡率和晶状体宏观形态变化以及SOD、MDA含量的变化。结果 G1和G2组模型死亡率分别为50%和10%,方法改良后死亡率显著降低;模型成功率分别为50%和90%,方法改良后成功率显著提高;两组模型晶状体混浊度一般为Ⅱ级或Ⅲ级;与C组比较,G1和G2组SOD、MDA含量的变化均有极显著差异（P﹤0.01）,而G2与G1组比较,差异不显著。结论半乳糖性白内障动物模型制备方法改良后,保留了改良前模型制备方法的优点,克服了改良前模型成活率低、死亡率高的缺点,是一种更为安全、可靠的模型制备方法 。     

脑缺血再灌注大鼠模型eNOS和nNOS的变化

目的通过对缺血再灌注早期eNOS与nNOS表达情况的观察,探讨NO在脑缺血再灌注损伤中发挥神经毒性作用时是否出现一氧化氮合酶(NOS)不同亚型的变化。方法采用线栓法制作大鼠脑缺血再灌注模型,激光多普勒灌流监测仪测血流来判断模型是否成功,Western blot方法检测eNOS与nNOS变化。结果血管内皮细胞内eNOS表达在缺血1h内升高,之后到再灌注2h内持续降低;而nNOS的表达在缺血到再灌注2h内持续上升。结论大鼠脑缺血再灌注模型中eNOS与nNOS的变化趋势不同。表明NO在缺血性脑损伤的病理过程的发挥作用与NOS亚型的变化有关。     

原花青素对脑缺血再灌损伤大鼠模型的影响

目的研究原花青素对脑缺血/再灌损伤(ischemia/reperfusion,I/R)大鼠神经功能评分(neurologicaldeficit score,NDS)、脑梗死体积、脑含水量等指标的药理作用。方法采用大鼠大脑中动脉阻断(middle cerebralartery occlusion,MCAO)法复制类似人类缺血性卒中的I/R损伤模型。结果该模型各时间点内均有程度不同的神经功能缺失,原花青素给药组神经功能评分明显低于对照组(P0.05),假手术组大鼠均无神经功能缺失,脑水肿情况均较对照组明显改善(P0.05),脑梗死体积与盐水对照组相比差异有显著性(P0.05),而假手术组均未见有梗死灶。结论原花青素具有一定的保护大鼠I/R后受损脑组织的作用,可供后续研究,并可为缺血性卒中使用原花青素治疗提供确凿的理论依据。     

Cellular Distribution and Subcellular Localization of mCLCA1/2 in Murine Gastrointestinal Epithelia

mCLCA1/2 are members of the CLCA protein family that are widely expressed in secretory epithelia, but their putative physiological role still awaits elucidation. mCLCA1/2 have 95% amino acid identity, but currently no specific antibody is available. We have generated a rabbit polyclonal antibody (pAb849) against aa 424–443 of mCLCA1/2. In HEK293 cells transfected with mCLCA1; pAb849 detected two specific protein bands at ∼125 kDa and 90 kDa, representing full-length precursor and N-terminal cleavage product, respectively. pAb849 also immunoprecipitated mCLCA1 and labeled the protein by immunostaining. But pAb849 crossreacted with mCLCA3/4/6 despite ≤80% amino acid identity of the antigenic epitope. We therefore investigated the cellular localization of mCLCA1/2 in epithelial tissues, which do not express mCLCA3/4/6 (salivary glands, pancreas, kidney) or express mCLCA3/6 with known localization (mucus cells of stomach and small intestine; villi of small intestine). mCLCA1/2 mRNA and protein expression were found in both parotid and submandibular gland, and immunohistochemistry revealed labeling in parotid acinar cells, in the luminal membrane of parotid duct cells, and in the duct cells of submandibular gland. In exocrine pancreas, mCLCA1/2 expression was restricted to acinar zymogen granule membranes, as assessed by immunoblotting, immunohistochemistry, and preembedding immunoperoxidase and immunogold electron microscopy. Moreover, mCLCA1/2 immunolabeling was present in luminal membranes of gastric parietal cells and small intestinal crypt enterocytes, whereas in the kidney, mCLCA1/2 protein was localized to proximal and distal tubules. The apical membrane localization and overall distribution pattern of mCLCA1/2 favor a transmembrane protein implicated in transepithelial ion transport and protein secretion. (J Histochem Cytochem 58:653–668, 2010)     

Increased corticosterone levels in mice subjected to the rat exposure test

In recent years, there has been a notable interest in studying prey-predator relationships to develop rodent-based models for the neurobehavioral aspects of stress and emotion. However, despite the growing use of transgenic mice and results showing important differences in the behavioral responses of rats and mice, little research has been conducted regarding the responses of mice to predators. The rat exposure test (RET), a recently developed and behaviorally validated prey-predator (mouse-rat)-based model, has proven to be a useful tool in evaluating the defensive responses of mice facing rats. To further validate the RET, we investigated the endocrine and behavioral responses of mice exposed to this apparatus. We first constructed a plasma corticosterone secretion curve in mice exposed to a rat or to an empty cage (control). Rat-exposed mice showed a pronounced rise in corticosterone levels that peaked 15 min from the beginning of the predator exposure. The corticosterone levels and behavioral responses of mice exposed to a rat or to a toy in the RET apparatus were then measured. We observed high plasma corticosterone levels along with clear avoidance behaviors represented by decreases in tunnel and surface area exploration and increases in risk assessment behaviors and freezing. This strongly suggests that the test elicits a repertoire of behavioral responses compatible with an aversion state and indicates that it is a promising model for the evaluation of prey-predator interactions. However, more physiological, neurochemical, and pharmacological studies are needed to further validate the test.     

Ontogenesis of rat immune system: Proteasome expression in different cell populations of the developing thymus

Immune proteasomes in thymus are involved in processing of self-antigens, which are presented by MHC class I molecules for rejection of autoreactive thymocytes in adults and probably in perinatal rats. The distribution of immune proteasome subunits LMP7 and LMP2 in thymic cells have been investigated during rat perinatal ontogenesis. Double immunofluorescent labeling revealed LMP7 and LMP2 in thymic epithelial and dendritic cells, as well as in CD68 positive cells - macrophages, monocytes - at all developmental stages. LMP2 and LMP7 were also detected by flow cytometry in almost all thymic CD90 lymphocytes through pre- and postnatal ontogenesis. Our results demonstrate that the immune proteasomes are expressed in all types of thymic antigen presenting cells during perinatal ontogenesis, suggesting the establishment of the negative selection in the thymus at the end of fetal life. The observation of the immune proteasome expression in T lymphocytes suggests their role in thymocyte differentiation besides antigen processing in thymus.     

The effect of levamisole and levamisole + vitamin C on oxidative damage in rats naturally infected with Syphacia muris

This study was performed to determine the effects of levamisole and levamisole + vitamin C against Syphacia muris naturally infection in rats and to detect its effect on the oxidative parameters in blood and tissues of host. For this purpose, natural infection was diagnosed using the cellophane tape method on the perianal region of rats. Infected rats (total 18) were divided into three groups. On the other hand six without helminth rats were used in this study as negative control group. Group 2 was given an orally levamisole HCl treatment with gastric gavage at a dose level of 20 mg/kg body weight in distilled water, every alternate day. Group 3 was given levamisole HCl via gastric gavage at a dose level of 20 mg/kg and vitamin C was given 1 g/L added to the drinking water. All the treatments continued for a period of 7 days. As a result; levamisole administered to rats at dose of 20 mg/kg orally 98.34% was found to be effective against adult S. muris in the rats. In addition to levamisole + vitamin C is effective to alleviate the oxidative damage in rats infected with S. muris.     

Trypanosoma evansi: Cholinesterase activity in acutely infected Wistar rats

The aim of this study was to evaluate cholinesterase activity during the early acute phase of Trypanosoma evansi infection in rats. Fifteen male Wistar rats were randomly distributed into three groups (n = 5 animals per group): two trypanosome-infected groups (T3 and T5) and uninfected controls (C). The animals were inoculated intraperitoneally with 10⁶ trypanosomes. The blood was collected by cardiac puncture on the 3rd (T3) or 5th day post-infection (T5 and C). Cerebrum and cerebellum were removed for the evaluation of acetylcholinesterase (AChE) activity. AChE activity was also evaluated in whole blood and butyrylcholinesterase activity (BUChE) in plasma samples. Parasitemia were progressive increase and parasites were observed in the peripheral blood of all infected animals one day post-inoculation. AChE activity was not altered in cerebrum and cerebellum tissues. AChE activity in blood significantly decreased in the T3 and T5 groups (26.63 and 25.86 mU/l mol Hb) compared with the control (37.84 mU/l mol Hb). In addition BUChE activity in plasma was lower in the T3 (7.01 μmol BTC hydrolyzed/h/mL) than the T5 and C groups (9.84 and 12.00 μmol BTC hydrolyzed/h/mL). This study therefore, shows that reductions in the activity of cholinesterase occur in acute infection by T. evansi in rats and this demonstrates an important change occurring in animals infected by the protozoan and may indicate a potential role the enzymes play in the mechanism of disease.     

Cell Type Specific Signalling by Hematopoietic Growth Factors in Neural Cells

Correct timing and spatial location of growth factor expression is critical for undisturbed brain development and functioning. In terminally differentiated cells distinct biological responses to growth factors may depend on cell type specific activation of signalling cascades. We show that the hematopoietic growth factors thrombopoietin (TPO) and granulocyte colony-stimulating factor (GCSF) exert cell type specific effects on survival, proliferation and the degree of phosphorylation of Akt1, ERK1/2 and STAT3 in rat hippocampal neurons and cortical astrocytes. In neurons, TPO induced cell death and selectively activated ERK1/2. GCSF protected neurons from TPO- and hypoxia-induced cell death via selective activation of Akt1. In astrocytes, neither TPO nor GCSF had any effect on cell viability but inhibited proliferation. This effect was accompanied by activation of ERK1/2 and inhibition of STAT3 activity. A balance between growth factors, their receptors and signalling proteins may play an important role in regulation of neural cell survival.