KATP通道开放剂吡那地尔对兔肺动脉平滑肌细胞增殖的影响

目的 :研究吡那地尔 (pinacidil,Pin)对内皮素 1(ET 1)诱导培养的兔肺动脉平滑肌细胞 (PASMC)增殖的影响。方法 :内皮素 1刺激培养兔PASMC增殖模型 ;以氚 胸腺嘧啶核苷 ([3 H] TdR)掺入法观察细胞增殖及脱氧核糖核苷酸 (DNA)合成 ;流式细胞仪技术检测兔PASMC细胞周期。结果 :吡那地尔可剂量依赖性的抑制内皮素 1所致的 [3 H] TdR掺入量增多 ,阻止兔PASMC由静止期 (G0 G1期 )进入DNA合成期 (S期 )和有丝分裂期 (G2 M期 )。ATP敏感性钾通道 (KATP)阻断剂格列本脲可拮抗吡那地尔对 [3 H] TdR掺入的抑制作用。结论 :吡那地尔可能通过激活KATP通道抑制内皮素 1诱导兔肺动脉平滑肌细胞的增殖 ,可望用于治疗肺动脉高压时所致的肺动脉重构。     

钾通道开放剂比那地尔对卵巢癌细胞增殖及凋亡的影响

目的 研究钾通道开放剂比那地尔对卵巢癌细胞(SKOV3)增殖和凋亡的作用.方法 将比那地尔(浓度分别为10、50、200、500 mmol·L-1)作用于卵巢癌细胞,用MTT法检测细胞活性,采用Hoechest33258荧光染色检测细胞凋亡,同时通过碘化丙啶(PI)染色,采用流式细胞仪检测细胞凋亡比率.结果 比那地尔对SKOV3细胞的增殖抑制效应具有剂量依赖性特点,并能诱导SKOV3细胞凋亡.结论 钾通道对SKOV3细胞增殖具有重要调控作用,钾通道开放剂可促进细胞凋亡.     

新型K_(ATP)开放剂埃他卡林对慢性低氧诱导大鼠体内肺动脉平滑肌K_(ATP)通道mRNA表达变化的影响

目的研究慢性低氧对大鼠肺动脉平滑肌KATP通道mRNA表达的影响及新型KATP开放剂埃他卡林(Iptakalim,IPT)的作用。方法将清洁级SD大鼠30只随机分成对照组、低氧组、IPT组,每组10只。将低氧组与IPT组放入常压低氧舱制备动物模型;采用右心导管测量大鼠肺动脉压;用实时荧光定量PCR检测(Real time PCR)技术分析各组肺动脉平滑肌KATP通道Kir6.1与SUR2B mRNA表达。结果低氧组大鼠肺动脉平均压高于对照组和IPT组(P<0.05),低氧组SUR2B亚基mRNA水平低于对照组(P<0.05),IPT可逆转慢性低氧对SUR2B的作用,各组Kir6.1亚基mRNA表达水平无差异(P>0.05)。结论慢性缺氧导致大鼠肺动脉平滑肌KATP通道SUR2B mRNA表达减少,IPT能拮抗慢性缺氧对KATP通道SUR2B mRNA基因表达的抑制作用。     

新型KATP开放剂iptakalim对豚鼠哮喘模型气道反应性及其结构的影响

目的 :研究新型KATP 通道开放剂 (KATPCO )iptakalim对哮喘豚鼠气道重塑、气道高反应性的作用。方法 :卵蛋白 (OA)制作哮喘模型 ,地塞米松组在吸入OA前先给予地塞米松 ;iptakalim高剂量治疗组和低剂量治疗组每天吸入OA前分别灌胃给Ipt0 .75mg·kg-1和 1.5mg·kg-1。用多道生理记录仪记录豚鼠气管螺旋条对不同浓度组织胺的收缩反应性 ;用图像分析仪测定细支气管内周长 (PI)、管壁面积 (WA)、管壁平滑肌面积 (SA) ,PI对WA、SA进行标准化 ,分别以WA PI、SA PI表示。结果 :组织胺可使各组豚鼠气管螺旋条产生剂量依赖性收缩。哮喘组豚鼠气管螺旋条对组织胺的收缩反应明显高于正常组 (P <0 .0 5 ) ;iptakalim(灌服 ) 0 .75、1.5mg·kg-1均具有同雾化吸入地塞米松相似的降低气管螺旋条收缩反应效果 (P >0 .0 5 )。对无软骨且平滑肌成环的细支气管图像分析显示 ,哮喘组豚鼠支气管壁面积 (2 9.8± 4 .5 μm2 ·μm-1)及支气管平滑肌面积(11.7± 4 .7μm2 ·μm-1)较正常对照组 (13.2± 5 .7,4 .4± 2 .1μm2 ·μm-1)增大 (P <0 .0 1) ,iptakalim使豚鼠管壁厚度和平滑肌厚度明显下降 ,与正常组比较差异不显著 (P >0 .0 5 )。结论 :口服新型KATP 通道开放剂iptakalim可抑制哮喘豚鼠气道高反应性和气道壁的重构。     

哮喘豚鼠气道平滑肌细胞内钙释放通道的变化

目的检测哮喘豚鼠气道平滑肌细胞(ASMCs)内钙释放通道功能的改变,探讨与支气管哮喘的关系,同时,寻找传代培养ASMCs的方法。方法以Flou-3/AM为细胞内钙离子示踪剂,观察ASMCs在工具药作用下细胞内钙离子浓度([Ca2+]i)的改变。结果①在ASMCs外无钙情况下,不同浓度ryanodine(5×10-5,10-4,2×10-4mol·L-1)作用于原代培养正常与哮喘ASMCs,[Ca2+]i迅速升高,哮喘组明显高于正常组(P<0·01)。10-4mol·L-1的组织胺(hista-mine)作用于原代培养的正常组与哮喘组ASMCs,[Ca2+]i升高无差异(P>0·05)。②传代培养哮喘ASMCs在10-4、2×10-4mol·L-1ryanodine作用下,[Ca2+]i迅速升高,与原代细胞比较无差异(P>0·05)。在浓度为5×10-5mol·L-1时,原代明显高于传代(P<0.01)。哮喘组传代ASMCs对10-4mol·L-1的histamine反应不明显。结论哮喘豚鼠ASMCs内钙释放通道(RyRs)功能升高,特定条件下,哮喘传代细胞仍然保持原代细胞内钙释放通道的特性。     

钾通道开放剂对培养兔主动脉平滑肌细胞增殖的抑制作用

钾通道开放剂对培养兔主动脉平滑肌细胞增殖的抑制作用１史道华２，郭兆贵（湖南医科大学药理研究室，长沙４１００７８，中国）关键词血管平滑肌；胸主动脉；培养的细胞；细胞分裂；苯福林；钾通道目的：探讨吡那地尔（Ｐｉｎ），尼可地尔（Ｎｉｃ），ＲＰ４９３５６（Ｒ...     

钾通道开放剂对培养兔主动脉平滑肌细胞增殖的抑制作用

目的：探讨吡那地尔（Ｐｉｎ），尼可地尔（Ｎｉｃ），ＲＰ４９３５６（ＲＰ）及雷马克林（Ｌｅｍ）对苯福林（ＰＥ）诱导的培养兔胸主动脉平滑肌细胞（ＡＳＭＣ）增殖的影响。 方法：测定［＾３Ｈ］胸腺嘧啶掺入ＡＳＭＣ ＤＮＡ的放射活性及细胞数目。 结果：Ｐｉｎ，Ｎｉｃ，ＰＲ及Ｌｅｍ对ＰＥ诱导的［＾３Ｈ］胸腺嘧啶摄取具有明显的抑制作用。对正常细胞的生长，仅ＲＰ具有抑制［＾３Ｈ］胸腺嘧啶摄取的作用。在Ｐｉｎ组，Ｐ     

1,25-二羟维生素D_3对哮喘大鼠气道平滑肌细胞增殖及RhoA表达的影响

目的观察1,25-(OH)_2D_3对哮喘大鼠AMSCs增殖及Rho A表达的影响,探讨其在哮喘治疗中的作用。方法用卵白蛋白致敏和激发建立急性哮喘模型,原代培养急性哮喘大鼠的ASMCs,以1,25-(OH)_2D_3作为干预因素,CCK8法检测1,25-(OH)_2D_3对ASMCs增殖的影响,测定细胞增殖活力;用TNF-α、1,25-(OH)_2D_3和地塞米松(DXM)处理体外培养的急性哮喘大鼠ASMCs并分组:对照组(N)、哮喘组(A组)、1,25-(OH)_2D_3组(VD组)、DXM组、1,25-(OH)_2D_3+DXM联合治疗组(L组)。用Transwell小室检测细胞迁移;流式细胞仪测定细胞周期。同时采用Real time PCR和Western blot方法检测肺组织和ASMCs中Rho A的表达变化,研究其作用机制。结果 1,25-(OH)_2D_3在10-9~10-6mol/L浓度下能显著抑制ASMCs的增殖,且为浓度依赖性(P<0.05);1,25-(OH)_2D_3对哮喘大鼠的ASMCs的抗增殖作用呈现时间依赖性;1,25-(OH)_2D_3对哮喘大鼠的ASMCs迁移有明显的抑制作用;1,25-(OH)_2D_3显著抑制哮喘大鼠ASMCs细胞周期中G1/S期的转化;1,25-(OH)_2D_3抑制并减少了Rho A/Rho激酶信号通路中RhoA基因和蛋白的表达。结论 1,25-(OH)_2D_3能显著抑制哮喘大鼠ASMCs的增殖、迁移及细胞周期的进展,这种多重的抑制作用可能是其通过调控Rho A/Rho激酶信号通路而实现其调节哮喘气道炎症、AHR和气道重塑的作用机制之一。     

钾通道阻滞剂对大鼠支气管平滑肌细胞增殖的影响

目的探讨电压依赖性延迟整流钾通道(K_V)、Ca²⁺激活钾通道(K_Ca)和ATP敏感性钾通道(K_ATP)对大鼠支气管平滑肌细胞(BSMC)增殖的影响。 方法应用免疫细胞化学、MTT微量比色分析法及流式细胞术,观察K_V,K_Ca和K_ATP对培养中大鼠BSMC增殖的影响。结果K_V阻断剂4-氨基吡啶(4-AP)显著促进大鼠BSMC增殖细胞核抗原的表达,提高BSMC吸光度值,使S+G₂M期细胞数显著增多,并显著提高基础状态下BSMC内Ca²⁺浓度,而K_Ca阻断剂四乙铵(TEA)和K_ATP阻断剂格列本脲(Glib)均无此效应。 结论大鼠BSMC K_V活性的抑制,可提高细胞内Ca²⁺浓度,促进细胞的增殖,而K_Ca和K_ATP对BSMC的增殖均无明显影响。     

川芎嗪抑制大鼠气道平滑肌细胞增殖的作用

目的探讨川芎嗪对大鼠气道平滑肌细胞(airway smooth muscle cells,ASMCs)增殖的影响。方法采用酶消化法和改良组织块法培养原代大鼠气道平滑肌细胞。MTT法检测血小板源生长因子(platelet-derived growth factor,PDGF)与川芎嗪共同处理的大鼠ASMCsA490的吸光度值,以观察川芎嗪对PDGF诱导的细胞增殖的抑制作用。Western blot检测ERK1/2及p-ERK1/2蛋白表达水平。结果 MTT法检测,与各对照组比较,给予12.5、25、50、100和200μmol.L-1浓度川芎嗪处理6、12、24、36和48h后,各浓度组川芎嗪处理的细胞平均抑制率均增加,P<0.05,其中以200μmol.L-1在48h时效果最明显,P<0.01。川芎嗪(200μmol.L-1)与PDGF(20pg·L-1)共同处理30min和60min后,p-ERK1/2蛋白表达水平均明显降低。结论川芎嗪对增殖的ASMCs有抑制作用,可能与抑制ERK1/2的信号通路活化有关。     

血管平滑肌的ATP敏感钾通道

ＡＴＰ敏感钾通道（ＫＡＴＰ）是一类较广泛分布的内向整流钾通道。在生理状态及某些病理条件下ＫＡＴＰ参与血管张力的调节。ＫＡＴＰ活性受多种因素的调控,胞内二磷酸核苷酸（ＮＤＰｓ）、钾通道开放剂（ＫＣＯｓ）等可激活通道,而ＡＴＰ和硫脲类药物则特异性抑制通道的开放。分子生物学研究证明ＫＡＴＰ由Ｋｉｒ６０和硫脲类受体（ＳＵＲ）共同组成,Ｋｉｒ６０构成Ｋ＋可穿透的通道核心,ＳＵＲ受体构成通道的调节单位。血管平滑肌中的ＫＡＴＰ是由Ｋｉｒ６１和ＳＵＲ２Ｂ组成的四聚体结构。但两种亚单位如何联结成有功能的多聚体还需进一步的证明。     

ATP敏感性钾通道的阻断剂与开放剂研究进展

ATP敏感性钾通道是高血压、心绞痛、糖尿病及缺血性脑损伤等多种疾病的治疗靶点之一。通过对调节KATP通道药物的选择性、可逆性、作用位点以及相互调节的研究，可以对一些临床用药进行重新评估，并指导开发高选择性的KATP通道阻断剂和开放剂。     

The supplementation of zinc increased the apoptosis of airway smooth muscle cells by increasing p38 phosphorylation

Proliferation of airway smooth muscle cells (ASMCs) is believed to play an important role in causing airway hyperresponsiveness (AHR). It has also been reported that platelet-derived growth factor (PDGF) can stimulate proliferation of ASMCs. We hypothesize that the concentration of zinc in the bodies of asthmatic patients may play a role in PDGF activity and therefore may be related to the variations in severity of airway inflammation and narrowing seen in asthmatic patients. We investigated the effects and mechanisms of zinc supplementation in PDGF-treated ASMCs.In this study, PDGF-treated primary ASMCs were cultured with 3, 12, 24, or 96 μM ZnSO₄. We found that the highest concentration of ZnSO₄ (96 μM) was cytotoxic for ASMCs. PDGF was used to induce ASMCs proliferation under different zinc concentrations. Neither 3 μM nor 12 μM ZnSO₄ inhibited proliferation of PDGF-treated ASMCs, although 24 μM ZnSO₄ caused treatment-induced apoptosis in PDGF-treated ASMCs. Supplementation with 24 μM ZnSO₄ may therefore increase p38 activation and reduce Akt phosphorylation. Zinc supplementation may reduce proliferation of PDGF-treated ASMCs through the activation of p38 mitogen-activated protein kinase (MAP kinase) and suppression of Akt phosphorylation, which both drive the induction of cellular apoptosis, subsequently reducing the proliferation of ASMCs.     

Inhibition of voltage-dependent K+ channels by iloperidone in coronary arterial smooth muscle cells

Iloperidone, a second-generation atypical antipsychotic drug, is widely used in the treatment of schizophrenia. However, the side-effects of iloperidone on vascular K⁺ channels remain to be determined. Therefore, we explored the effect of iloperidone on voltage-dependent K⁺ (Kv) channels in rabbit coronary arterial smooth muscle cells using the whole-cell patch-clamp technique. Iloperidone inhibited vascular Kv channels in a concentration-dependent manner with a half-maximal inhibitory concentration (IC₅₀) of 2.11 ± 0.5 μM and a Hill coefficient of 0.68 ± 0.03. Iloperidone had no effect on the steady-state inactivation kinetics. However, it shifted the steady-state activation curve to the right, indicating that iloperidone inhibited Kv channels by influencing the voltage sensors. Application of 20 repetitive depolarizing pulses (1 and 2 Hz) progressively increased the inhibition of the Kv current in the presence of iloperidone. Furthermore, iloperidone increased the recovery time constant from Kv channel inactivation, suggesting that iloperidone-induced inhibition of Kv channels is use (state)-dependent. Pretreatment with a Kv1.5 inhibitor (diphenyl phosphine oxide 1 [DPO-1]) inhibited the Kv current to a level similar to that with iloperidone alone. However, pretreatment with a Kv2.1 or Kv7.X inhibitor (guangxitoxin or linopirdine) did not affect the inhibitory effect of iloperidone on Kv channels. Therefore, iloperidone directly inhibits Kv channels in a concentration- and use (state)-dependent manner independently of its antagonism of serotonin and dopamine receptors. Furthermore, the primary target of iloperidone is the Kv1.5 subtype.     

Cl~-通道在内皮素-1引起的血管平滑肌细胞增殖中的作用

目的　研究Cl-通道在内皮素 1(endothelin 1,ET 1)引起的血管平滑肌细胞增殖中的作用 ,并探讨其可能的作用机制。方法　通过细胞计数和3H TdR参入实验 ,并结合fura 2 /AM荧光测定胞浆游离Ca2 + 浓度 ([Ca2 + ]i)等技术 ,观察了Cl-通道阻断剂对ET 1引起的 [Ca2 + ]i 变化及血管平滑肌细胞增殖的影响。结果　Cl-通道阻断剂DIDS可呈浓度依赖性地抑制 10nmol·L-1ET 1引起的血管平滑肌细胞增殖 ,其它Cl-通道阻断剂如IAA 94、NPPB、SITS、DPC和速尿均无此作用 ,DIDS也能抑制 10nmol·L-1ET 1引起的内流相 [Ca2 + ]i 升高 ,而对ET 1引起的Ca2 + 释放无影响 ;预先将细胞与 1μmol·L-1nifedipine作用后 ,3μmol·L-1DIDS对 10nmol·L-1ET 1引起的内流相 [Ca2 + ]i 升高及血管平滑肌细胞增殖不再有效 ,将细胞与 10 μmol·L-1SK&F96 36 5预孵后 ,DIDS却能进一步抑制ET 1的上述作用 ;3μmol·L-1DIDS对 30mmol·L-1KCl引起的胞浆[Ca2 + ]i升高无影响。结论　DIDS可通过阻断Cl-通道来抑制ET 1因促发Cl-通道开放经电压依赖性钙通道的Ca2 +内流及细胞增殖 ,DIDS敏感的Cl-通道可能在ET 1促发的Ca2 + 内流及血管平滑肌细胞增殖的调控上都起着重要的作用     

Proteomic analysis of the effect of iptakalim on human pulmonary arterial smooth muscle cell proliferation

Aim： To investigate the anti-proliferative effect of iptakalim （Ipt）, a newly selective KATP channel opener, in endothelin-1（ET-1）-induced human pulmonary arterial smooth muscle cells （PASMCs） using proteomic analysis. Methods： Human PASMCs were incubated with ET-1 （10^-8mol/L） and ET-1 （10^-8mol/L） plus iptaklim （10^-5mol/L） for 24 h. Analysis via 2-DE gel electrophoresis and MALDI-TOF-MS was employed to display the different protein profiles of whole-cell protein from cultures of control, ET-1 treatment alone, and treatment with ET-1 and iptaklim combined. Real time RT-PCR and Western blot analysis were used to confirm the proteomic analysis. Results： When iptakalim inhibited the proliferative effect of ET-1 in human PASMCs by opening the KATp channels, the expression of different groups of cellular proteins was changed, including cytoskeleton-associated proteins, plasma.membrane proteins and receptors, chaperone proteins, ion transport-associated proteins, and glycolytic and metabolism-associated proteins. We found that iptakalim could inhibit the proliferation of human PASMCs partly by affecting the expression of Hsp60, vimentin, nucleoporin P54（NUP54） and Bcl-XL by opening the KATP channel. Conclusion： The data suggest that a wide range of signaling pathways may be involved in abolishing ET-1-induced proliferation of human PASMCs following iptakalim treatment.     

埃他卡林对兔肺动脉平滑肌内皮细胞钙浓度的影响

目的观察埃他卡林(IPT)对内皮素1(ET-1)诱导培养的兔肺动脉平滑肌细胞(PASMC)增殖的影响,并探讨其作用机制。方法应用细胞培养、氚-胸腺嘧啶核苷([3H]-TdR)参入实验、Fluo-3和激光扫描共聚焦显微镜技术评价IPT对ET-1诱导的兔PASMC增殖及PASMC[Ca2+]i调节的作用。结果ET-1(10-7mol.L-1)使PASMC[3H]-TdR参入量增加146.8%,与对照组比较,差异有显著性(P<0.01);在相同条件下,加入ET-1的同时,分别向培养基中加入IPT10-7、10-6、10-5mol.L-1,细胞[3H]-TdR参入量分别下降(19.8±4.6)%、(41.2±9.5)%、(54.7±10.1)%,与ET-1组比较差异有显著性(P<0.01);对照组PASMC[Ca2+]i荧光强度和荧光光密度值较低;ET-1组中[Ca2+]i荧光光密度值明显增高,从73.7±10.1增加到143.8±28.2,两者比较差异有显著性(P<0.01);而IPT组细胞内荧光光密度值明显降低,仅从74.30±10.2增加到86.03±9.82,与ET-1组比较差异有显著性(P<0.01)。结论IPT可明显抑制ET-1诱导的兔PASMC增殖、DNA合成;减少钙通道的开放时间,抑制细胞内Ca2+浓度增加。     

Paracetamol inhibits Ca2+ permeant ion channels and Ca2+ sensitization resulting in relaxation of precontracted airway smooth muscle

The purpose of this study was to screen a bronchodilator from old drugs and elucidate the underlying mechanism. Paracetamol (acetaminophen) is a widely used analgesic and antipyretic drug. It has been reported that it inhibits the generation of prostaglandin and histamine, which play roles in asthma. These findings led us to explore whether paracetamol could be a potential bronchodilator. Paracetamol inhibited high K⁺- and acetylcholine (ACH)-induced precontraction of mouse tracheal and bronchial smooth muscles. Moreover, the ACH-induced contraction was partially inhibited by nifedipine (selective blocker of LVDCCs), YM-58483 (selective inhibitor of store-operated Ca²⁺ entry (SOCE), canonical transient receptor potential 3 (TRPC3) and TRPC5 channels) and Y-27632 (selective blocker of ROCK, a linker of the Ca²⁺ sensitization pathway). In single airway smooth muscle cells, paracetamol blocked the currents sensitive to nifedipine and YM-58483, and inhibited intracellular Ca²⁺ increases. In addition, paracetamol inhibited ACH-induced phosphorylation of myosin phosphatase target subunit 1 (MYPT1, another linker of the Ca²⁺ sensitization pathway). Finally, in vivo paracetamol inhibited ACH-induced increases of mouse respirator system resistance. Collectively, we conclude that paracetamol inhibits ASM contraction through blocking LVDCCs, SOCE and/or TRPC3 and/or TRPC5 channels, and Ca²⁺ sensitization. These results suggest that paracetamol might be a new bronchodilator.