Further confirmation of heterogeneity of the rat striatum: Different mosaic patterns of dopamine fibers after administration of methamphetamine or reserpine

Heterogeneity of adult rat neostriatum has been studied by fluorescence histochemistry. The distribution of dopamine nerve fibers and terminals, known normally to be homogeneous, tended to become heterogeneous after administration of methamphetamine or reserpine. Both drugs caused mosaic formations of fluorescent dopamine axons and terminals, though a minor difference was present in the pattern of distribution. The results indicate that the striatum possesses at least two types of dopamine nerve terminals, sensitive and relatively insensitive for the two catecholamine depletors.     

转基因中国仓鼠卵细胞中单胺囊泡转运体抗毒性作用的研究

目的:研究转基因中国仓鼠卵(CHO)细胞中单胺囊泡转运体(VMAT_2)的抗毒性作用。方法:利用转PC12细胞基因到CHO细胞中形成的转基因CHO细胞(cDNA-CHO),采用MTT比色法检测1-甲基-4-苯基吡啶离子(MPP~+)对CHO细胞野生株(wtCHO)和cDNA-CHO细胞的毒性作用,并观察利血平——VMAT_2的特异性阻滞剂对MPP~+毒性作用的影响。结果:在MPP~+ 0.5mmol/L以上浓度cDNA-CHO细胞对MPP~+敏感性比wtCHO低得多;cDNA-CHO和wtCHO对鱼藤酮(rotenon)的敏感性无显著差异;加入利血平后,上述保护作用消失,cD-NA-CHO对MPP~+敏感性与wtCHO细胞无差异,而单独予以wtCHO细胞利血平则不能改变它对低浓度MPP~+的敏感性。结论:此保护机制是由转基因细胞中VMAT_2引起的,VMAT_2在转基因的非神经细胞系(CHO细胞系)中也能将MPP~+转运至囊泡内,从而保护细胞,同时也提示PC12细胞内具有抗毒性作用的成分。     

胞内储备钙参与3,4-二氨基吡啶诱发去甲肾上腺素释放(英文)

目的:用大鼠海马脑片研究3,4-氨基吡啶(DAP)诱发去甲肾上腺素胞外钙-不依赖释放的机制。方法:大鼠海马脑片用[~3H]NE孵育后,进行表面灌流,测[~3H]NE释放。结果:在胞外无钙条件下,DAP能显著加强[~3H]NE释放,当用利血平使囊泡[~3H]NE排空,则DAP作用消失,用高浓度地昔帕明刺激IP_3-敏感的胞内Ca~(2 )储备库,能有力地增强[~3H]NE释放,而高浓度咖啡因对[~3H]NE释放只有很微弱的作用,丹曲林钠对DAP诱发[~3H]NE释放无任何抑制作用。结论:在胞外无钙条件下,DAP通过IP_3-敏感的Ca~(2 )储备库释放Ca~(2 ),从而诱发囊泡内的去甲肾上腺素释放。     

HPLC法测定复方降压平片中利血平的含量

目的 :建立高效液相色谱法测定复方降压平片中利血平的含量。方法 :采用 C1 8(2 0 0 mm× 4 .6 mm,5 μm)色谱柱 ,乙腈 -水 (4 1:5 9)用高氯酸调节 p H值至 (2 .15± 0 .0 5 )为流动相 ,检测波长 2 6 8nm。结果 :利血平在 4 .0 0～ 16 .0 0μg/ml浓度范围内与峰面积呈良好线性关系 (r =0 .9996 ) ,平均回收率为 10 0 .5 % ,RSD =0 .34% (n =9)。结论 :该方法简便、准确、可靠     

红毛五加总甙的镇痛作用

红毛五加甙（ＴＧＡ，ｉｇ２００－８００ｍｇ·ｋｇ－１）能显著抑制小鼠热板、扭体、嘶叫反应及大鼠甩尾反应。连续给药７ｄ，镇痛作用无耐受现象。小鼠和大鼠ｉｃｖ２０ｍｇ（相当ｉｇ有效剂量的１／１０，可明显提高其痛阈。纳洛酮（２ｍｇ·ｋｇ－１）、利血平（４ｍｇ·ｋｇ－１）不影响ＴＧＡ的镇痛作用。ＴＧＡ还能明显降低大鼠足跖炎症组织中ＰＧＥ的含量。结果提示，ＴＧＡ具有镇痛作用，其作用部位可能在中枢，但可能不是通过兴奋阿片受体或影响脑内单胺类递质而发挥作用的；对ＰＧＥ含量的影响，可能是ＴＧＡ发挥镇痛作用的外周因素     

液相色谱质谱联用(LC-MS/MS)在天然化学成分分析中的应用Ⅰ.音喷离子化(SSI)与大气压化学离子化(APCI)对利血平的比较分析

报道应用 L C- MS/ MS,采用音喷离子化 (SSI)与大气压化学离子化 (APCI)对利血平的比较分析 ,应用这两种离子化方法比较所得的利血平的标准质谱 (MS)和二级质谱 (MS2 ) ,实验证明两种离子化方法所得结果完全一致     

复方降压片对高血压大鼠冠状动脉壁肥厚和储备力下降的影响

目的 研究复方降压片对高血压大鼠冠状动脉壁肥厚和储备力下降的影响。方法 4w大鼠设4组：分别为自发性高血压大鼠(SHR)组、SHR口服复方降压片组、SHR口服卡托普利组和正常血压大鼠(WKY)组，饲养12w。冠脉最大血流量用离体心脏灌注法测定。结果 复方降压片能显著降低SHR收缩压、冠状动脉横截面积，提高最大冠状动脉流量，与卡托普利相似。复方降压片能降低SHR的左心室重与体重比，但仍然显著高于WKY组和口服卡托普利组。结论 复方降压片能预防SHR冠状动脉壁肥厚、储备力下降，减轻左心室肥厚；冠状动脉血流储备力的损害程度和左心室肥厚程度不平行。     

Molecular,Neurochemical, and Behavioral Hallmarks of Reserpine as a Model for Parkinson's Disease: New Perspectives to a Long‐Standing Model

The administration of reserpine to rodents was one of the first models used to investigate the pathophysiology and screening for potential treatments of Parkinson's disease (PD). The reserpine model was critical to the understanding of the role of monoamine system in the regulation of motor and affective disorders, as well as the efficacy of current PD treatments, such as L‐DOPA and dopamine agonists. Nevertheless, with the introduction of toxin‐induced and genetic models of PD, reserpine became underused. The main rationale to this drawback was the supposed absence of reserpine construct validity with PD. Here, we highlight classical and recent experimental findings that support the face, pharmacological, and construct validity of reserpine PD model and reason against the current rationale for its underuse. We also aim to shed a new perspective upon the model by discussing the main challenges and potentials for the reserpine model of PD.     

Rhes, the Ras homolog enriched in striatum, is reduced under conditions of dopamine supersensitivity

Striatal dopamine receptors become supersensitive when dopaminergic input is removed through either surgical denervation or pharmacological depletion. Although alterations such as increased D2 receptor binding and increased receptor-G protein coupling have been described in supersensitive striatal tissue, their roles in the mechanism of supersensitivity remain uncertain. The Ras Homolog Enriched in Striatum (Rhes) is expressed in brain areas that receive dopaminergic input, and here we test whether alterations in its expression accompany treatments that promote dopamine receptor supersensitivity in rats. Removal of dopamine input to the striatum by surgical denervation with 6-hydroxydopamine resulted in a decrease in rhes mRNA expression throughout striatum, as measured with quantitative in situ hybridization. The decrease was detected as early as two weeks and as late as seven months after surgery. Furthermore, a decrease in rhes mRNA was evident after repeated or acute reserpine treatment. Chronic daily injection of rats with the D2 antagonist eticlopride, which is known to up-regulate D2 receptors without inducing profound receptor supersensitivity, did not alter the expression of rhes mRNA in striatum. Thus, changes in rhes mRNA expression are strictly correlated with receptor supersensitivity, perhaps as a result of continuous removal of dopaminergic input. These findings suggest that rhes mRNA expression is maintained by dopamine and may play a role in determining normal dopamine receptor sensitivity.