NMDA对新生大鼠皮层神经元的兴奋毒作用

目的:建立NMDA诱导原代培养皮层神经元兴奋毒损伤模型,探讨NMDA对NMDA受体过度活化诱导兴奋性神经毒的可能途径。方法:原代培养新生大鼠大脑皮层神经元,通过倒置显微镜形态学观察、细胞活力检测(MTT及LDH释放的检测)及胞内Ca2+的动态测定,探索NMDA诱导毒性作用的适当浓度及时间。通过对ROS、NO检测,分析NMDA诱导毒性作用于线粒体的损伤情况。结果:NMDA(100μmol/L/2 h)引起皮层神经元形态学改变,且引起神经元细胞活力时间和浓度依赖性的下降,由同时伴随LDH释放增加(P<0.05),ROS和NO的生成量明显增加(P<0.05),皮层神经元内Ca2+的快速升高,并维持在高水平。结论:NMDA诱发皮层神经元明显的细胞毒性作用,提示NMDA过度活化NMDA受体后通过神经元膜内Ca2+超载造成ROS和NO的生成量增加,导致皮层神经元产生毒性损伤。     

补阳还五汤联合神经干细胞移植促进脊髓损伤髓鞘再生

目的:探讨补阳还五汤(BYHWD)灌胃联合神经干细胞(NSCs)移植对脊髓损伤(SCI)后髓鞘再生的影响.方法:将48只成年雌性SD大鼠随机分为脊髓损伤(SCI)组、BYHWD灌胃组、NSCs移植组、NSCs移植联合BYHWD灌胃(BYHWD+ NSCs)组.SCI组不做治疗;NSCs组于脊髓横断后局部移植NSCs; BYHWD+ NSCs组移植NSCs,并每天BYHWD灌胃;各组在损伤后14、28 d后分别留取损伤脊髓标本,用免疫荧光双标法检测髓磷脂碱性蛋白(MBP)表达情况,透射电镜观察脊髓白质内髓鞘超微结构变化.结果:BYHWD+ NSCs组MBP阳性表达最多,较其他3组差异有统计学意义.电镜下BYHWD+NSCs组髓鞘结构较为规整,轴突微丝、微管排列有序,线粒体结构完整,可见薄髓的再生髓鞘.结论:SCI后BYHWD灌胃联合NSCs移植能够促进损伤脊髓MBP的表达及脱髓的轴突再髓鞘化.     

Angiotensin-Converting Enzyme Inhibitor,Captopril, Improves Scar Healing in Hypertensive Rats

Pathological cutaneous scars, with aberrant extracellular matrix accumulation, have multiple origins. Antihypertensive medications, such as calcium channel blockers, have been used to treat pathological scars. However, a relationship between angiotensin-converting enzyme (ACE) inhibitors, pathological scars, and blood pressure (BP) has never been reported. Here, we aimed to compare the differences in scar development and the effects of the administration of systemic ACE inhibitor on scar tissue in a normotensive rat, the Wistar Kyoto rat (WKY), a hypertensive rat, and the spontaneously hypertensive rat (SHR). Using an 8-mm punch, we created two full-thickness skin defects in a total of 32 rats (16 WKY and 16 SHR) to obtain a total of 64 wounds. We established control WKY (n = 16), captopril-treated WKY (n = 16), control SHR (n = 16), and captopril-treated SHR (n = 16) groups and started captopril (100 mg/g per day) treatment on day 21 in the appropriate groups. The BP of all groups was measured at 0, 3, and 5 weeks. The scar area was measured by histopathological examination, and scarring was expressed in terms of scar area and fibroblast and capillary counts. The expression of heat shock protein (HSP) 47, type I and III collagens, alpha-smooth muscle actin (α-SMA), Ki67, and vascular endothelial growth factor (VEGF) was investigated using immunohistochemistry. The scar area and fibroblast count were significantly higher in control SHR than in control WKY. The scar area, fibroblast count, and capillary count were significantly smaller in captopril-treated SHR than in control SHR. Immunostaining for α-SMA, Ki67, and VEGF also showed a noticeable decrease in scarring in the treated SHR compared with that in control SHR. Thus, BP affects scar development in a rat model, and an ACE inhibitor is more effective at reducing scars in hypertensive rats than in normotensive rats.     

Iron accumulation in the choroid plexus,ependymal cells and CNS parenchyma in a rat strain with low‐grade haemolysis of fragile macrocytic red blood cells

Iron accumulation in the CNS is associated with many neurological diseases via amplification of inflammation and neurodegeneration. However, experimental studies on iron overload are challenging, since rodents hardly accumulate brain iron in contrast to humans. Here, we studied LEWzizi rats, which present with elevated CNS iron loads, aiming to characterise choroid plexus, ependymal, CSF and CNS parenchymal iron loads in conjunction with altered blood iron parameters and, thus, signifying non‐classical entry sites for iron into the CNS. Non‐haem iron in formalin‐fixed paraffin‐embedded tissue was detected via DAB‐enhanced Turnbull Blue stainings. CSF iron levels were determined via atomic absorption spectroscopy. Ferroportin and aquaporin‐1 expression was visualised using immunohistochemistry. The analysis of red blood cell indices and serum/plasma parameters was based on automated measurements; the fragility of red blood cells was manually determined by the osmotic challenge. Compared with wild‐type animals, LEWzizi rats showed strongly increased iron accumulation in choroid plexus epithelial cells as well as in ependymal cells of the ventricle lining. Concurrently, red blood cell macrocytosis, low‐grade haemolysis and significant haemoglobin liberation from red blood cells were apparent in the peripheral blood of LEWzizi rats. Interestingly, elevated iron accumulation was also evident in kidney proximal tubules, which share similarities with the blood–CSF barrier. Our data underscore the importance of iron gateways into the CNS other than the classical route across microvessels in the CNS parenchyma. Our findings of pronounced choroid plexus iron overload in conjunction with peripheral iron overload and increased RBC fragility in LEWzizi rats may be seminal for future studies of human diseases, in which similar constellations are found.     

经鼻腔给予丙酸睾丸酮对老年大鼠骨骼肌的改善作用

目的:探讨经鼻腔给予丙酸睾丸酮对老年大鼠骨骼肌生理功能和形态结构的改善作用.方法:老年雄性大鼠经鼻腔给予丙酸睾丸酮12周,利用倾斜面实验和水平绳实验观察大鼠的行为变化;H-E染色显示大鼠肱二头肌的形态变化.结果:老年大鼠鼻腔给予丙酸睾丸酮对体质量无明显影响;老年大鼠连续2d的倾斜面下滑角度减小,50°角下滑次数增加,水平绳悬挂时间缩短,鼻腔给予丙酸睾丸酮后连续2d的倾斜面下滑角度增加,50°角下滑次数减少,水平绳悬挂时间延长;老年大鼠单位面积内肱二头肌肌细胞间隔的比例增多,鼻腔给予丙酸睾丸酮后单位面积内肱二头肌肌细胞间隔的比例减少.结论:鼻腔给予丙酸睾丸酮可以提高老年大鼠的平衡反应能力和肌张力,增加肱二头肌肌细胞面积,对老年大鼠肌细胞的生理功能及形态结构起到一定的保护作用,为鼻腔应用丙酸睾丸酮治疗老化过程引起的肌肉减少症提供实验依据.     

不同缺血后处理方案对大鼠肾脏缺血再灌注损伤的保护作用

目的 试建立恰当的大鼠肾脏缺血再灌注损伤（IRI）的缺血后处理模型。方法 选8 ～ 12周健康60只SD雄性大鼠,体质量220 ～ 260 g。随机分为6组：对照组（S组）、缺血再灌注组（IR组）及IR缺血后处理A、B、C、D组,每组10只。S组：分离出双侧肾蒂,仅行右肾蒂结扎和左肾蒂游离;IR组：结扎右侧肾蒂,夹闭左侧肾蒂60 min后恢复灌注;缺血后处理A、B、C、D组在肾脏缺血60 min后分别进行6次（开放10 s ＋ 阻断10 s）、5次（开放20 s ＋ 阻断20 s）、3次（开放10 s ＋ 阻断10 s）、3次（开放2 min ＋ 阻断2 min）的循环,然后充分开放灌注。再灌注24 h后监测肾功能,对肾组织结构损伤程度评分。结果 与IR组相比,A、B、C、D组后处理的血尿素氮（BUN）、血肌酐（SCr）及肾小管损伤程度评分均降低（P 〈 0.05）,肾组织损伤明显减轻。处理组中,A、B两组的BUN、SCr及肾小管损伤程度评分相当（P 〉 0.05）,且缺血后处理效果优于C、D两组（P 〈 0.05）。结论： 采用缺血后处理A组方法和B组方法均可以成功制作出缺血后处理模型。     

放化疗性口腔黏膜炎动物模型研究进展

由放疗和(或)化疗诱发的口腔黏膜炎症,可能导致患者疼痛、说话吞咽困难、局部和全身感染风险增高,甚至中断抗癌治疗,严重影响患者生活质量。放化疗性口腔黏膜炎的发病机制复杂而且防治较为困难,而动物模型在探究放化疗性口腔黏膜炎的发病机制以及探索更好的防治方法中发挥了重要作用,本文就以现有的放化疗性口腔黏膜炎动物模型的复制及评估方法予以综述。文献复习结果表明,国内外采用小鼠、大鼠、金仓鼠等动物来复制动物模型;放疗诱发的口腔黏膜炎的诱导方法有仅采用X射线设备对动物进行局部单剂量照射或局部分割照射,或照射时辅助使用化疗药物5 氟尿嘧啶或顺铂,也可以采用137铯作为放射源进行局部照射;单纯使用化疗药物5 氟尿嘧啶诱发的口腔黏膜炎一般症状较轻,因此多采用5 氟尿嘧啶联合机械刺激或乙酸进行诱导;评估放化疗性口腔黏膜炎的方法主要为大体样本观察及组织病理学观察。