异丙酚对LPS诱导BV-2小胶质细胞IL-1β和TNF-α释放的影响及TLR4在其中的作用

目的 评价异丙酚对LPS诱导BV-2小胶质细胞IL-1β和TNF-α释放的影响及Toll样受体4(TLR4)在其中的作用.方法 将体外培养的BV-2小胶质细胞接种于96孔培养板中,采用随机数字表法,将其随机分为4(n=12):对照组、LPS组、异丙酚组和LPS+异丙酚组.LPS组加入LPS1μg/ml孵育24h;异丙酚组加入异丙酚30 μmol/L孵育24 h;LPS+异丙酚组同时加入LPS 1 μg/ml和异丙酚30 μmol/L孵育24h.于孵育6h时,采用ELISA法检测细胞上清液TNF-α浓度,以此反映TNF-α的释放量,采用RT-PCR法测定TLR4 mRNA表达;于孵育24h时,采用ELISA法检测细胞上清液IL-1β浓度,以此反映IL-1β的释放量,采用Western Blot法检测TLR4蛋白表达.结果 与C组比较,LPS组和LPS+异丙酚组IL-1β和TNF-α的释放量升高,TLR4 mRNA及其蛋白表达上调(P＜0.05);与LPS组比较,LPS+异丙酚组IL-1β和TNF-α的释放量降低,TLR4 mRNA及其蛋白表达下调(P＜0.05).结论 异丙酚可抑制LPS诱导BV-2小胶质细胞IL-1β和TNF-α的释放,其机制与抑制TLR4的表达有关.     

星型胶质细胞和小胶质细胞在1型糖尿病小鼠外周神经病变中的作用

目的 观察星形胶质细胞和小胶质细胞标志物在1型糖尿病外周神经病变小鼠脊髓中的表达变化。
方法 SPF级健康雄性C57BL/6小鼠30只,6周龄,体重18~22 g,采用随机数字表法分为两组：对照组（C组）和糖尿病组（DM组）。DM组采用链脲佐菌素（STZ）（100 mg/kg,连续2 d腹腔注射）制备1型糖尿病小鼠模型,C组给予同等剂量柠檬酸钠缓冲液连续2 d。记录两组小鼠造模前、造模后1、2、4、6、8、10周的体重、随机血糖、机械缩足反应阈（MWT）、热缩足潜伏期（TWL）。生化检测分别选取C组和DM组1周、10周的脊髓。采用Western blot法测定L4—L6脊髓脂肪酸结合蛋白7（FABP7）、星形胶质细胞特异性标记物胶质纤维酸性蛋白（GFAP）、小胶质细胞标记物（CD11b、iba1）表达量,Elisa法测定小鼠脊髓组织中肿瘤坏死因子α（TNF-α）、IL-10浓度,免疫组化法测定足底表皮神经纤维密度（IENFD）。
结果 与C组比较,DM组造模后2、4、6、8、10周体重、MWT明显降低（P＜0.05或P＜0.01）,造模后1、2、4、6、8、10周血糖明显升高（P＜0.01）,造模后4、6、8、10周TWL明显延长（P＜0.05或P＜0.01）;造模后1周FABP7和GFAP表达量明显升高（P＜0.05）;造模后10周FABP7、CD11b、iba1表达量明显升高（P＜0.05）;造模后10周脊髓组织中IL-10、TNF-α浓度明显升高（P＜0.05）;造模后10周IENFD明显降低（P＜0.05）。
结论 糖尿病模型小鼠造模后1周脊髓中星形胶质细胞活化但小胶质细胞无明显改变,而造模后10周星形胶质细胞已恢复正常但小胶质细胞活化,1型糖尿病外周神经病变中星型胶质细胞较小胶质细胞更早的激活。     

异丙酚预先给药对BV-2细胞缺氧复氧时TLR4表达的影响

目的 评价异丙酚对BV-2细胞缺氧复氧时Toll样受体4(TLR4)表达的影响.方法 小鼠小胶质细胞(BV-2细胞)于6孔培养板中培养4～6 d后随机分为4组(n=4),正常对照组(C组)不给予任何处理;缺氧复氧组(A/R组)缺氧3 h、复氧12 h;缺氧复氧+25μmol/L异丙酚组(P25组)和缺氧复氧+100μmol/L异丙酚组(P100组)于缺氧前30 min加入异丙酚,终浓度分别为25、100μmol/L.于复氧12 h时收集细胞,测定TLR4 mRNA、NF-κB mRNA和TLR4蛋白水平;收集细胞上清液,测定TNF-α水平.结果 与C组比较,A/R组、P25组和P100组TLR4 mRNA、NF-κB mRNA、TLR4蛋白和TNF-α水平均升高(P<0.01);与MR组比较,P25组和P100组TLR4 mRNA、NF-κB mBNA、TLB4蛋白和TNF-α水平均下降(P<0.01);与P25组比较,P100组TLR4 mRNA、NF-κB mRNA、TLR4蛋白和TNF-α水平均降低(P<0.01).结论 异丙酚25、100 μmol/L预先给药可抑制BV-2细胞缺氧复氧时TLR4 mRNA表达上调.     

七氟醚麻醉对大鼠海马α7烟碱型乙酰胆碱受体、胆碱酯酶和胆碱乙酰移位酶蛋白含量的影响

目的研究七氟醚麻醉对大鼠海马α7烟碱型乙酰胆碱受体(α7nAchR)、胆碱酯酶(AChE)、胆碱乙酰移位酶(ChaT)蛋白含量的影响。方法健康SD新生大鼠120只,雌雄不拘,1周龄,随机分为五组:空白组、空氧组、七氟醚组(SEV组)、α7nAchR激动剂组(PNU组)和α7nAchR拮抗剂组(MLA组),每组24只。空白组自由喂养;空氧组吸入60%的氧气即运载气体(1 L/min O_2+1 L/min空气)2 h;SEV组吸入3.4%七氟醚+运载气体2 h;PNU组单次腹腔注射α7nAchR激动剂PNU-282987,24 h后吸入3.4%七氟醚+运载气体2 h;MLA组单次腹腔注射α7nAchR拮抗剂甲基牛扁亭,24 h后吸入3.4%七氟醚+运载气体2 h。麻醉清醒后2 h、1周、4周取海马组织,采用Western blot法测定α7nAchR、AChE、ChaT蛋白含量。结果麻醉清醒后2 h SEV组、PNU组、MLA组α7nAchR蛋白含量明显低于空氧组(P0.05);PNU组、MLA组AChE蛋白含量明显高于空氧组(P0.05);SEV组、PNU组、MLA组ChaT蛋白含量明显低于空氧组(P0.05)。麻醉清醒后1周空白组、SEV组、PNU组海马中α7nAchR蛋白含量明显高于空氧组(P0.05),MLA组α7nAchR蛋白含量明显低于空氧组(P0.05);空白组、PNU组AChE蛋白含量明显高于空氧组(P0.05);空白组ChaT蛋白含量明显高于空氧组,SEV组ChaT蛋白含量明显低于空氧组(P0.05)。麻醉清醒后4周五组AChE蛋白含量差异无统计学意义;SEV组α7nAchR蛋白含量明显高于空白组,PUN组和MLA组明显低于空白组(P0.05);空白组、SEV组和PNU组ChaT蛋白含量明显低于空氧组,MLA组明显高于空氧组(P0.05)。结论吸入七氟醚后能抑制ChaT、α7nAChR;对AChE并无直接作用;α7nAChR激动剂能有效缓解吸入七氟醚对α7nAChR、ChaT抑制作用,并在1周左右达到高峰;氧浓度在60%左右能增加α7nAChR蛋白含量,一定程度对抗七氟醚抑制作用。     

内质网三磷酸肌醇受体在fractalkine诱发BV-2小胶质细胞p38MAPK信号通路激活中的作用

目的 探讨内质网三磷酸肌醇受体在fractalkine诱发BV-2小胶质细胞p38丝裂原活化蛋白激酶(p38MAPK)信号通路激活中的作用.方法 将BV-2小胶质细胞以1×105个/ml浓度接种于3.5 cm培养皿(5 ml/皿)、50 ml培养瓶(8 ml/瓶)、24孔培养板(1 ml/孔)或6孔培养板(2 ml/孔),采用随机数字表法,将其随机分为5组(n=25)∶正常对照组(C组)、fractalkine组(F组)、CX3C趋化因子受体1抗体anti-CX3CR1+ fractalkine组(CF组)、内质网三磷酸肌醇受体拮抗剂2-APB+ fractalkine组(AF组)及p38MAPK抑制剂SB203580+ fractalkine组(SF组).除C组外,其他4组加入10 nmol/L fractalkine,CF组、AF组及SF组于加入fractalkine前1h分别加入15 μmol/L anti-CX3CR1、50 μmol/L 2-APB及10 μmol/L SB203580.测定fractalkine孵育10 min期间细胞内Ca2+浓度([Ca2+]i)的最大值作为[Ca2+]i,于fractalkine孵育即刻、30、60、120、240 min时测定p38MAPK磷酸化水平,于fractalkine孵育24h时测定细胞培养液白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)浓度.结果 与C组比较,F组、CF组、AF组和SF组[Ca2+]i、p38MAPK磷酸化水平、IL-1β和TNF-α浓度升高(P＜0.05);与F组比较,CF组和AF组[Ca2+]i降低,CF组、AF组及SF组p38MAPK磷酸化水平、IL-1β和TNF-α浓度降低(P＜0.05).结论 内质网三磷酸肌醇受体参与了fractalkine诱发BV-2小胶质细胞p38MAPK信号通路激活.     

小胶质细胞与三磷酸腺苷在疼痛中的作用

大量证据表明,细胞内外三磷酸腺苷(adenosine 5'-triphosphate,ATP)在疼痛信号转导中起着重要作用.目前研究主要集中在ATP及其受体在慢性疼痛(尤其是神经病理性疼痛)中的作用及其可能机制.机体受到刺激后,激活的小胶质细胞会高表达P2X4受体和其他ATP受体,从而释放脑源性生长因子(brain-derived neurotrophic factor,BDNF)、白介素-1β(interleukin-1β,IL-1β)、白介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-a,TNF-α)和一氧化氮(nitric oxide,NO).了解这些ATP受体的重要作用将为慢性疼痛治疗提供新的策略.     

大麻素受体2在谷氨酸诱发小胶质细胞损伤中的作用

目的 评价大麻素受体2(CB2受体)在谷氨酸诱发小胶质细胞损伤中的作用.方法 采用随机数字表法,将小胶质细胞随机分为4组:对照组(C组)细胞常规培养26h;小胶质细胞损伤组(Ⅰ组)细胞于含10 mmol/L谷氨酸的培养基中孵育24h;CB2受体特异性激动剂AM1241组细胞于含2 μmol/L AM1241的培养基中孵育2h,然后于含10 mmol/L谷氨酸的培养基中孵育24 h;CB2受体特异性拮抗剂AM630组细胞含2 μmol/L AM630的培养基中孵育2h,然后于含10 mmol/L谷氨酸的培养基孵育24h.测定细胞活力和LDH释放量,观察细胞形态学.结果 与C组比较,Ⅰ组、AM1241组和AM630组细胞活力降低,LDH释放量增加(P＜0.05);与Ⅰ组比较,AM1241组细胞活力升高,LDH释放量减少(P＜0.05),AM630组细胞活力和LDH释放量差异无统计学意义(P＞0.05).结论 谷氨酸通过抑制CB2受体的功能诱发小胶质细胞损伤.     

氯胺酮对大鼠脊髓背角星形胶质细胞的保护机制

目的 探讨氯胺酮对N-甲基-D天冬氨酸（NMDA）诱导的大鼠脊髓背角星形胶质细胞损伤的保护机制。方法 取新生2～3dWistar大鼠40只T12～L5脊髓背角星形胶质细胞，原代纯化培养3周。将细胞随机分六组：NMDA组（N组），氯胺酮组（K组）、NMDA加不同浓度氯胺酮组（标记为NK1～NK3组），对照组（C组）。加药后培养30min或24h取各组细胞检测超氧化物岐化酶（SOD）活性和丙二醛（MDA）含量，免疫细胞化学观察Bcl-2／Bax表达，流式细胞仪检测星形胶质细胞凋亡率和胞内游离钙浓度（[Ca^2＋]i）。结果 与C组比较，N组细胞发生大量凋亡（P〈0．01），Bax强阳性表达，Bcl-2阴性表达，SOD活性显著降低（P〈0．01），MDA含量明显增加（P〈0．01），[Ca^2＋]i显著升高（P〈0．01）。与N组比较，NK2、NK3组细胞凋亡明显减少（P〈0．05或P〈0．01），Bcl-2阳性表达，Bax阴性表达，[Ca^2＋]i低（P〈0．05或P〈0．01），SOD活性增加（P〈0．01），MDA含量低（P〈0．01）。结论 氯胺酮抑制激活的背角星形胶质细胞内Ca^2＋超载，增强Bcl-2蛋白表达，抑制NMDA诱导的细胞凋亡，并增强抗氧化酶活性，抑制脂质过氧化反应引起的细胞损伤。     

小鼠天然CD4^＋CD25^＋调节性T细胞表达α7烟碱型乙酰胆碱受体

目的探讨C57BL／6J小鼠的天然CD4^＋CD25^＋调节性T细胞（CD4^＋CD25^＋Treg）是否存在α7烟碱型乙酰胆碱受体（α7nAchR）。方法使用小鼠调节性T细胞试剂盒分离小鼠脾脏CD4^＋CD25^＋Treg,流式细胞术鉴定CD4^＋CD25^＋Treg的纯度。分别采用免疫荧光染色、共聚焦显微镜、Western印迹和逆转录聚合酶链反应检测Treg表面α7nAchR蛋白／基凶表达：结果α-银环蛇毒素-FITC染色、流式检测显示Treg细胞表面结合α-银环蛇毒素-FITC;共聚焦显微镜成像观察到Treg细胞表面结合大量α-银环蛇毒索;Western印迹检测证实Treg细胞样本中检测到了清楚的α7nAchR条带,分子量大小约为55kD;RT-PCR分析发现Treg细胞样本中检测到了199bp大小的特异性α7nAchR目的基因条带。结论小鼠天然CD4^＋CD25^＋Treg细胞表达α7nAChR。     

吗啡对大鼠大脑皮质星形胶质细胞神经甾体水平的影响

目的 研究吗啡对大鼠大脑皮质星形胶质细胞神经甾体水平的影响。方法 建立原代新生SD大鼠大脑皮质星形胶质细胞吗啡依赖样模型，并随机分为4组：生理盐水对照组（c组）、吗啡组（M组）、μ受体拮抗剂CTAP＋吗啡组（C＋M组）和扯受体选择性激动剂DAMGO组（D组）。固相萃取结合高效液相色谱．质谱联用法测定细胞培养上清液中神经甾体孕烯醇酮（PREG）、脱氢表雄酮（DHEA）、别孕烯醇酮（AP）、硫酸孕烯醇酮（PS）和硫酸脱氢表雄酮（DS）水平；RT-PCR法观察P450侧链裂解酶（P450scc）转录活性；免疫印迹法观察细胞内p-CREB水平。结果 与C组比较，M组PREG、AP和DS、D组PREG、AP和DS下降（P〈0．05或0．01），P450sccmRNA的表达降低、细胞内p-CREB升高（P〈0．05）；与M组比较，C＋M组PREG和DHEA升高、PS下降（P〈0．05或0．01），P450BccmRNA表达增强、p-CREB降低（P〈O．05）。结论 吗啡可通过扯阿片受体抑制P450scc的转录，影响大鼠大脑皮质星形胶质细胞对神经甾体的合成。     

烟碱对内毒素血症大鼠凝血功能的影响

目的 探讨烟碱对内毒素血症大鼠凝血功能的影响.方法 成年健康雄性SD大鼠96只,体重200～250 g,采用随机数字表法,将大鼠随机分为4组(n=24):生理盐水对照组(NS组)、内毒素组(LPS组)、烟碱组(NIC组)、α7烟碱型乙酰胆碱受体(α7nAchR)拮抗剂组(α-BGT组).LPS组、NIC 组和α-BGT组经股静脉注射脂多糖(LPS)10 mg/kg制备内毒素血症模型.α-BGT组于注射LPS前45min腹腔注射α-BGT 1μg/kg,注射α-BGT后15 min腹腔注射烟碱400 μg/kg.NIC组除用等容量生理盐水替代α-BGT外,余操作同α-BGT组.LPS组除用等容量生理盐水替代烟碱外,余操作同NIC组.NS组除用等容量生理盐水替代LPS外,余操作同LPS组.于注射LPS前、注射后2、4、6 h时采集腹主动脉血样,检测血浆凝血酶原时间(PT)、部分活化凝血活酶时间(APTT)、纤维蛋白原(Fib)、抗凝血酶(AT)、血管性血友病因子(vWF)、纤溶酶原激活物抑制物-1(PAI-1)、D-二聚体、肿瘤坏死因子-α(TNF-α)水平和血小板计数.结果 与NS组比较,LPS组和α-BGT组PT、APTT延长,血浆Fib、AT水平降低,血小板计数减少,血浆PAI-1、WF、D-二聚体与TNF-α水平升高(P＜0.05).与LPS组比较,NIC组PT、APTT缩短,血浆Fib和AT水平升高,血小板计数增加,血浆PAI-1、vWF、D-二聚体和TNF-α水平降低(P＜0.05).与NIC组比较,α-BGT组PT和APTT延长,血浆Fib和AT水平降低,血小板计数减少,血浆PAI-1、vWF、D-二聚体和TNF-α水平升高(P＜0.05).结论 烟碱可抑制内毒素血症大鼠过度激活的凝血反应,缓解抗凝血与纤维蛋白溶解功能的抑制状态,作用机制可能与其结合外周α7烟碱型乙酰胆碱受体激活胆碱能抗炎通路,从而减少促炎性细胞因子释放有关.

Abstract：

Objective To investigate the effect of nicotine on coagulation abnormalities in endotoxemic rats.Methods Ninety-six male SD rats weighing 200-250 g were randomly divided into 4 groups (n=24 each): group normal saline (group NS);group LPS;group nicotine(group NIC)and group α-bungarotoxin (α7 nicotinic acetylcholine receptor antagonist, group α-BGT) . Endotoxemia was induced by LPS 10 mg/kg injected via femoral vein in LPS, NIC and α-BGT groups. In group NIC nicotine 400 μg/kg was injected intraperitoneally at 30 min before LPS injection. In group α-BGT α-BGT 1 μg/kg was injected intraperitoneally at 15 min before intraperitoneal nicotine. Prothrombin time(PT),activated partial thromboplastin time(APTT),fibrinogen(Fib),antithrombin (AT),von Willebrand factor(vWF),plasminogen activator inhibitor-1(PAI-1),D-dimer,platelet count and TNF-α were measured before (baseline) and 2, 4 and 6 h after LPS injection.Results PT and APTT were significantly prolonged and plasma Fib and AT concentrations and platelet count were significantly decreased, while plasma PAI-1, D-dimer, vWF and TNF-α concentrations were significantly increased after LPS administration in group LPS as compared with group NS. Nitotine pretreatment significantly attenuated the LPS-induced changes in group NIC.The effect of nicotine was counteracted by α-BGT. Conclusion Nicotine can attenuate coagulation abnormalities induced by LPS by acting on α7 nicotinic acetylcholine receptor.     

Apoptosis of spinal cord neurons by preventing depletion nicotine attenuates arachidonic acid-induced of neurotrophic factors

Increased levels of free fatty acids and, in particular, arachidonic acid can lead to induction of apoptosis of spinal cord neurons. Because of the importance of neurotrophic factors in cell survival and death, mRNA and protein levels of brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor (FGF-2) were studied in cultured spinal cord neurons treated with arachidonic acid. In addition, the present study focused on the effects of nicotine and neuronal nicotinic acetylcholine receptors (nAChRs) on these processes. A 2-h exposure to arachidonic acid markedly diminished expression of BDNF and FGF-2. These effects were fully prevented by pretreatment with 10 microM nicotine. Mecamylamine (a non-specific antagonist of nAChRs) and alpha-bungarotoxin (a specific antagonist of the nAChRalpha7) completely inhibited nicotine-mediated protection against arachidonic acid-induced alterations of BDNF and FGF-2. In addition, nicotine, BDNF and FGF-2 fully protected against arachidonic acid-induced apoptosis of spinal cord neurons. BDNF and FGF-2 were effective in prevention of apoptotic cell death even when applied 2 h after the beginning of arachidonic acid treatment. These results suggest that arachidonic acid can induce apoptosis of spinal cord neurons by depletion of neurotrophic factors and that nicotine can protect against these effects through the nAChRalpha7-mediated pathway.     

小鼠天然CD4~+CD25~+调节性T细胞表达α7烟碱型乙酰胆碱受体

目的 探讨C57BL/6J小鼠的天然CD4~+CD25~+调节性T细胞(CD4~+CD25~+Treg)是否存在α7烟碱型乙酰胆碱受体(a7nAchR).方法 使用小鼠调节性T细胞试剂盒分离小鼠脾脏CD4~+CD25~+Treg,流式细胞术鉴定CD4~+CD25~+Treg的纯度.分别采用免疫荧光染色、共聚焦湿微镜、Western印迹和逆转录聚合酶链反应检测Treg表面α7nAchR蛋白/基因表达.结果 α-银环蛇毒素-FITC染色、流式检测显示Treg细胞表面结合α-银环蛇毒素-FITC;共聚焦显微镜成像观察到Treg细胞表面结合大量α-银环蛇毒素;Western印迹检测证实Treg细胞样本中检测到了清楚的α7nAchR条带,分子量大小约为55 kD;RT-PCR分析发现Treg细胞样本中检测到了199 bp大小的特异性α7nAchR目的 基因条带.结论小鼠天然CD4~+CD25~+Treg细胞表达α7nAChR.     

Buflomedil and pentoxifylline in the viability of dorsal cutaneous flaps of rats treated with nicotine.

BACKGROUND: Nicotine reduces skin-flap survival. Pharmacologic therapy may represent an alternative treatment strategy to counteract nicotine effects in the flap surgery setting. In this study, we have compared the isolated and associated actions of the vasoactive drugs buflomedil and pentoxifylline in the viability of dorsal cutaneous flaps of rats treated with subcutaneous doses of nicotine. METHODS: The survival of modified McFarlane skin flaps was assessed on post-operative day 7. Nicotine group received 4 mg/kg nicotine during 40 days pre-operatively and 7 days post-operatively. Nicotine+buflomedil group received nicotine and 6 mg/kg buflomedil 24 h pre-operatively and 7 days post-operatively. Nicotine+pentoxifylline group received nicotine and 20 mg/kg pentoxifylline in 15 pre-operatively and 7 post-operatively days. Nicotine+buflomedil+ pentoxifylline group received nicotine and both drugs administered as above. Control group received daily 1 ml normal saline during 40 days pre-operatively and 7 days post-operatively. Using image analysis, five different flap areas were quantified: Total, preserved, necrotic, ischaemic and viability. Viability areas comprised the sum of ischaemic and preserved areas. RESULTS: Nicotine treated animals had lower percentage of viability areas (60.7% +/- 6.8) than the control group (73.7% +/- 9.5), p=0.016. The percentage of viability areas in the buflomedil (76.4% +/- 11.4), pentoxifylline (74.2% +/- 15.6) and buflomedil+ pentoxifylline (74.0% +/- 9.7) groups were larger than the nicotine group (p=0.002, p=0.011 and p=0.012, respectively). There were no significant differences in the viability areas when drugs were used isolated or in association. We further demonstrated that the increase in the viability area of the buflomedil and pentoxifylline groups (isolated or in association) was due to increase in ischaemic areas. CONCLUSIONS: Both drugs equally increased flap survival in nicotine treated animals. Viability areas increased due to larger ischaemic areas, probably as a reflex of the action of these drugs in sites of partial circulatory deficit.     

尼古丁对大鼠骨髓间充质干细胞软骨分化的干预作用研究

目的 从细胞水平证实尼古丁对大鼠骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)诱导分化为软骨细胞的干预作用.方法 大鼠BMSCs传代至第3代,以海藻酸钠微球生物支架进行BMSCs三维培养.加入转化生长因子β1(TGF-β1)进行诱导分化,在细胞分化过程中,分别给予0.1、1、10、100μmol/L尼古丁干预,设对照组.第28天收获细胞,采用四甲基偶氮唑蓝(MTT)法检测细胞代谢活力、阿利新蓝特殊染色检测细胞中氨基葡聚糖的含量、实时荧光定量PCR检测软骨分化标志基因(COL2A1、Aggrecan、COL1A1、COL10A1)的表达情况.结果 诱导培养28 d后,MTT法结果示不同浓度尼古丁干预后的各组细胞代谢活力与对照组细胞相比,没有明显改变;当尼古丁作用浓度分别为0、0.1、1、10和100μmol/L时,其BMSCs海藻酸钠微球的阳性染色区域占切片的百分比分别为90.1％、76.5％、64.8％、44.1％、4.5％;与对照组比较,尼古丁能显著抑制软骨诱导分化下的BMSCs细胞中Aggrecan、COL2A1的表达,同时促进COL1A1、COL10A1的表达(P均<0.05),并且存在浓度依赖性.结论 尼古丁能够明显抑制大鼠BMSCs的软骨分化,导致其软骨分化质量差.     

咪达唑仑对新生大鼠心肌细胞缺氧/复氧时细胞凋亡的影响

目的 探讨咪达唑仑对新生大鼠心肌细胞缺氧/复氧时细胞凋亡的影响.方法 分离、培养出生2～4 d的Wistar大鼠心肌细胞,将培养融合的心肌细胞随机分为7组(n=7):正常对照组(C组)、缺氧/复氧组(HR组)、外周型苯二氮革类受体(PBR)拮抗剂PK 11195组(P组)、PBR激动剂Ro 5-4864组(R组)、咪达唑仑组(M组)、PK 11195+Ro 5-4864组(PR组)和PK 11195+咪达唑仑组(PM组).HR组缺氧30 min复氧2 h建立缺氧/复氧模型.P组、R组、M组、PR组、PM组在培养皿中分别加入终浓度为10-4mol/L的PK 11195、Ro 5-4864和咪达唑仑及相应混合药物共同孵育,30 min后行缺氧/复氧.复氧2 h时收集细胞,采用HTC-Annexin V/PI双标法检测细胞凋亡情况,计算细胞凋亡指数(AI);Western blot法测定心肌细胞蛋白激酶C(PKc)表达水平;Meta Flour单细胞内钙测定系统测定细胞内钙离子浓度.结果 与C组比较,其余各组AI升高,除R组外其余各组细胞内钙离子浓度升高,PKC表达下调(P<0.01);与HR组比较,R组AI和细胞内钙离子浓度降低,PKC表达上调,M组和PM组AI降低(P<0.01);与P组比较,R组AI和细胞内钙离子浓度降低,PKC表达上调(P<0.01),PR组、PM组差异无统计学意义(P>0.05);与R组比较,M组、PR组、PM组Al和细胞内钙离子浓度均升高,PKC表达下调(P<0.01).结论 咪达唑仑10-4mol/L可减轻新生大鼠心肌细胞缺氧/复氧时细胞凋亡,其作用机制可能是非PBR依赖性的,且与细胞内钙离子浓度和PKC表达无关.     

烟碱对大鼠心肌缺血再灌注损伤的影响

目的 探讨烟碱对大鼠心肌缺血再灌注损伤的影响.方法 健康成年雄性SD大鼠74只,体重200～250 g,随机分为5组:假手术组(S组,n=10)、缺血再灌注组(IR组,n=16)、烟碱400 μg/kg组(N1组,n=16)、烟碱40 μg/kg组(N2组,n=16)和α-银环蛇毒素组(α-BGT组,n=16).S组只穿线,不结扎左冠状动脉前降支;余各组采用结扎左冠状动脉前降支30 min,再灌注60 min的方法 制备大鼠心肌缺血再灌注模型.缺血前30 min时,N1组和N2组经右颈静脉分别注射烟碱400和40 μg/kg,α-BGT组右颈静脉注射N型胆碱能受体α-7亚单位特异性阻断剂α-银环蛇毒素1.0 μg/kg+烟碱400 μg/kg,S组和IR组右颈静脉注射等量生理盐水.再灌注60 min时,IR组、N1组、N2组和α-BGT组各取6只大鼠,测定左心室面积(LVA)、缺血危险区面积(AAR)和梗死区面积(IA),计算AAR/LVA和IA/LVA.再灌注60 min时,各组取10只大鼠,采集右颈动脉血样,测定血浆肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)的浓度和肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)的活性;然后处死动物,取心肌组织,观察心肌超微结构,测定心肌髓过氧化物酶(MPO)活性.结果 与S组比较,IR组、N1组、N2组、α-BGT组血浆 TNF-α、IL-1β的浓度和CK-MB、LDH的活性升高,心肌MFO活性升高(P<0.05);与IR组比较,N1组IA/LVA、血浆TNF-α、IL-1β的浓度和CK-MB、LDH的活性、心肌MPO活性降低(P<0.05),心肌细胞超微结构损伤减轻,N2组和α-BGT组上述指标差异无统计学意义(P>0.05);与N1组比较,N2组和α-BGT组IA/LVA、血浆TNF-α、IL-1β的浓度和CK-MB、LDH的活性、心肌MPO活性升高(P<0.05),心肌细胞超微结构损伤加重.结论 烟碱可减轻大鼠心肌缺血再灌注损伤,其机制可能与激活胆碱能抗炎通路,抑制炎性反应有关.     

Changes in blood perfusion and bone healing induced by nicotine during distraction osteogenesis

Nicotine is the main chemical in cigarettes responsible for the tobacco's pathological effects. The influence of nicotine on bone healing remains controversial. Distraction osteogenesis provides an ideal model to study bone healing and regeneration. The present study aims to evaluate the effects of nicotine on blood perfusion, angiogenesis and bone formation using a rabbit model of mandibular lengthening. Twenty adult New Zealand white rabbits were randomly assigned to the control group and nicotine group. The total nicotine or placebo exposure time for all animals was 7 weeks. After 2- or 4-week of consolidation following osteotomy, 3-day of latency and 11-day of active distraction, the animals were sacrificed and the mandibles were harvested. Blood perfusion and vascularization were evaluated by Laser Doppler monitoring and Collagen IV immunohistochemistry staining respectively. Bone formation was assessed by radiological, histological and immunohistochemical examination. Results showed that nicotine exposure increased microvessel density, whereas inhibited blood flow and bone formation. The expression of bone morphogenetic protein (BMP)-2 in osteoblasts was also decreased. Frequent appearance of cartilage islands suggested ischemia and low oxygen tension in the distraction regenerate. We concluded that nicotine compromises bone regeneration possibly by causing ischemia and directly inhibitory effect on osteoblastic cells. Nicotine exposure enhances angiogenesis but cannot compensate for the adverse effect of vasoconstriction.