缬沙坦对血管平滑肌细胞增殖与迁移及丝裂原活化蛋白激酶的影响

目的:观察缬沙坦对血管紧张素Ⅱ(AngⅡ)刺激下大鼠胸主动脉平滑肌细胞(VSMC)的增殖与迁移及磷酸化P42/44丝裂原活化蛋白激酶(MAPK)表达的影响。方法:组织贴块法培养大鼠胸主动脉平滑肌细胞,应用丝裂原活化蛋白激酶(MTT)分析检测细胞的增殖能力,transwell小室检测细胞的迁移能力,Western blot检测磷酸化P42/44MAPK蛋白表达的水平。结果:(1)AngII能明显促进血管平滑肌细胞的增殖与迁移,该作用可被缬沙坦和MAPK激酶的特异性抑制剂PD98059所抑制。(2)AngⅡ刺激血管平滑肌细胞5min时,磷酸化P42/44MAPK的表达量最大,该作用也可被缬沙坦和P     

丝裂素活化蛋白激酶的激活和转核与大鼠 血管平滑肌细胞增殖关系的研究

目的 探讨丝裂素活化蛋白激酶（MAPK）激活、转核与血管紧张素Ⅱ（AngⅡ)刺激血管平滑肌细胞（VSMC）增殖间的关系。方法 本实验采用培养大鼠胸主动脉VSMC。用^3H-胸腺嘧啶核苷（^3H-TdR)掺入法测定DNA合成,用p43/p44磷酸化抗MAPK抗体的蛋白免疫印迹法测定MAPK蛋白量,用免疫细胞化学技术观察MAPK活化并转位入细胞核的过程。结果 （1）AngⅡt和PD98059的上述作用都呈剂量依赖性。（2）AngⅡ对MAPK蛋白表达有显著增强作用。此作用同样被PD98059以剂量依赖方式抑制。（3）AngⅡ刺激5min后,MAPK出现在VSMC的细胞浆中,30min时MAPK进入细胞核,3h后MAPK染色从核内消失,上述MAPK转核过程被PD98059抑制。结论 本实验证实人细胞核,3h后MAPK染色从核人消失,上述MAPK转核过程被PD98059抑制。结论 本实验证实AngⅡ能激活培养大鼠主动脉VSMC的MAPK,活化的MAPK从细胞浆转位进入细胞核导致VSMC增殖。     

血管紧张素Ⅱ对大鼠腹膜间皮细胞表达纤维连接蛋白的影响及其作用机制

目的：观察血管紧张素Ⅱ（AngⅡ）对大鼠腹膜间皮细胞（RPMCs）纤维连接蛋白（FN）表达的影响，以及有丝分裂原活化蛋白激酶通路（mitogen—activated protein kinases，MAPKs）在AngⅡ诱导FN表达中所起的作用。方法：酶消化法于大鼠大网膜中分离间皮细胞，以AngⅡ刺激后，分别应用realtime．PCR及Western印迹法检测FN的表达情况。应用Western印迹法观察AngⅡ（1μmol／L）对MAPK通路的主要信号传导蛋白ERK1／2、p38MAPK和JNK活化的影响，并分别应用ERK1／2、p38MAPK和JNK的抑制剂以及AngⅡ的Ⅰ型受体（AT1）阻断剂进行干预，Western印迹法观察上述抑制剂对AngⅡ诱导FN表达的影响。结果：AngⅡ促进RPMCs表达FN，活化ERK1／2和p38MAPK信号传导通路，而不影响JNK通路的活化。ERK1／2通路抑制剂PD98059及AT1受体阻断剂（losartan）可明显抑制AngⅡ诱导的FN表达增加，而p38MAPK和JNK抑制剂对FN的表达无影响。结论：AngⅡ促进RPMCs合成FN增多。AT1受体和ERK1／2通路介导了AngⅡ诱导RPMCs表达FN。     

血管平滑肌细胞细胞周期素依赖性激酶抑制因子的调节

目的 阐明有丝分裂源激活的蛋白激酶(MAPK)和磷脂酶C(PLC)通路在调节细胞周期紊依赖性激酶抑制因子(CKI)p27，p21，p57蛋白表达量中的作用及其对血管平滑肌细胞(VSMC)增殖的影响。方法 分离SD大鼠主动脉中层平滑肌，贴壁法培养平滑肌细胞，无血清培养基培养静止后，分别加入血小板源性生长因子(PDGF)(20ng／m1)、PDGF PD98059(20ng／ml 20mmol／L)、PDGF 硫酸新霉紊(20ng／ml 10mmol／L)等刺激因素，以无血清培养基培养的VSMC作对照。在刺激后90min收集细胞，用免疫沉淀法检测MAPK(p44／p42)活性的改变。在刺激后6和24h收集细胞，用Western蛋白印迹法检测p27、p57和p21蛋白表达量。结果 PDGF刺激后，MAPK活性明显升高(较对照组增加46．6％)，同时VSMC明显增殖。刺激24h后，细胞增殖程度为对照组的1．43倍，p27蛋白的表达量显著下降至对照组的71％；p21和p57蛋白表达量却明显增加；加用PD98058(MAPK抑制剂)和新霉紊(PLC抑制剂)可明显抑制PDGF引起的上述改变，MAPK活性分别较PDGF。刺激组下降了46％和37％，p27蛋白表达量则分别为PDGF刺激组的1．77倍和1．49倍，细胞增殖程度分别降为后者的68％和65％。结论 MAPK(-14／42)变化的幅度是决定CKI表达量和VSMC增殖的关键因素。PLC通路在PDGF刺激VSMC增殖信号转导中同样起关键作用。     

大鼠血管平滑肌细胞迁移能力变化与血管紧张素Ⅱ的关系

目的　研究血管紧张素Ⅱ（AngⅡ）及其受体拮抗剂对培养的大鼠血管平滑肌细胞（VSMC）迁移能力影响,以探讨AngⅡ介导高血压、动脉粥样硬化和血管成形术后再狭窄斑块形成的生物学机制。方法　采用改良Boyden小室,对不同浓度AngⅡ及其AT1R、AT2R拮抗剂作用下VSMC跨膜迁移细胞数进行评价。结果　AngⅡ在一定的浓度范围内（10-11～10-7mol/L）可以剂量依赖性地刺激体外培养的大鼠VSMC发生迁移。迁移的VSMC数在AngⅡ浓度为10-7mol/L时达到峰值,更高浓度的AngⅡ（10-6mol/L）干预VSMC后,VSMC迁移数量的增加幅度反而比较低浓度的AngⅡ作用时减小（与10-7mol/LAngⅡ组比较,P<0.01）。AT1R拮抗剂CV-11974剂量依赖性抑制AngⅡ诱导VSMC跨膜迁移,AT2R拮抗剂PD123319对此无影响。结论　AngⅡ在AT1R介导下发挥其影响VSMC迁移行为的生物学效应,较低浓度AngⅡ促进VSMC迁移,高浓度AngⅡ上述作用明显减弱。     

大鼠血管平滑肌细胞迁移能力变化与血管紧张素Ⅱ的关系

目的 研究血管紧张素Ⅱ(AngⅡ）及其受体拮抗剂对培养的大鼠血管平滑肌细胞（VSMC）迁移能力影响,以探讨AngⅡ介导高血压、动脉粥样硬化和血管成形术后再狭窄斑块形成的生物学机制。方法 采用改良Boyden小室,对不同浓度AngⅡ及其AT1R、AT2R拮抗剂作用下VSMC跨膜 迁移细胞数进行评价。结果 AngⅡ在一定的浓度范围内（10^-11～10^-7mol/L）可以剂量依赖性地刺激体外培养的大鼠VSMC发生迁移。迁移的VSMC数在AngⅡ浓度为10^-7mol/L时达到峰值,更高浓度的AngⅡ(10^-6mol/L）干预VSMC后,VSMC迁移数量的增加幅度反而比较低浓度的AngⅡ作用时减小（与10^-7mol/L AngⅡ组比较,P＜0．01）。AT1R拮抗剂CV－11974剂量依赖性抑制AngⅡ诱导VSMC跨膜迁移,AT2R拮抗剂PD123319对此无影响。结论 AngⅡ在AT1R介导下发挥其影响VSMC迁移行为的生物学效应,较低浓度AngⅡ促进VSMC迁移,高浓度AngⅡ上述作用明显减弱。     

粉防已碱对AngⅡ诱导血管平滑肌细胞增殖及NF-κB通路的影响

采用血管紧张素Ⅱ（AngⅡ）诱导培养Wistar大鼠胸主动脉血管平滑肌细胞（VSMC），MTT比色法测定粉防已碱（Tet）对血管平滑肌细胞抑制增殖率；考马斯亮蓝法测定蛋白含量；免疫印记法测定NF-κB（p65）及其抑制物（I-κBα）表达；凝胶电泳迁移率分析测定核转录因子-κB（NF-κB）体外活性。发现Tet能显著抑制血管平滑肌细胞增殖；抑制VSMC胞核NF-κB表达，同时抑制胞浆I-κBα磷酸化；同时显著抑制NF-κB体外活性。提示Tet明显抑制AngⅡ诱导的VSMC增殖，机制与调控NF-κB通路有关。     

人白细胞介素10对血管紧张素Ⅱ诱导的大鼠血管平滑肌细胞增殖的作用

目的观察重组人白介素10 (rhIL-10) 对血管紧张素Ⅱ(AngⅡ)刺激下离体大鼠胸主动脉血管平滑肌细胞增殖及对p44/p42 丝裂素活化蛋白激酶的影响. 方法体外培养大鼠主动脉血管平滑肌细胞,采用MTS/PES(methoxyphenyl-tetrazolium salt/phenazine ethosulfate)法确定血管平滑肌细胞的增殖状态.利用p44/p42磷酸化抗丝裂素活化蛋白激酶抗体的蛋白免疫印迹法测定丝裂素活化蛋白激酶蛋白的表达;对照组为未用AngⅡ刺激的血管平滑肌细胞. 结果 AngⅡ对大鼠血管平滑肌细胞增殖具有明显的刺激作用(1.311±0.201 对 0.781 ±0.236, P<0.05).rhIL-10单独应用对血管平滑肌细胞生长没有影响(0.783±0.170 对 0.781±0.236, P>0.05).在AngⅡ刺激下,1、10、100 ng/ml的rhIL-10均可抑制血管平滑肌细胞的生长 (分别为0.984±0.172、 0.932±0.134、 0.784±0.097对1.311±0.201, P<0.05).AngⅡ对p44/p42 丝裂素活化蛋白激酶蛋白表达有显著的增强作用(512±78对100,P< 0.01), 此作用可被rhIL-10抑制 (512±78对329±59, P< 0.01). 结论 rhIL-10可抑制AngⅡ诱导的血管平滑肌细胞增殖及p44/p42 丝裂素活化蛋白激酶蛋白的表达.     

血管紧张素Ⅱ介导的大鼠血管平滑肌细胞STAT1激活与核转位

目的 检测血管紧张素Ⅱ（AngⅡ）介导的大鼠血管平滑肌细胞（VSMC）增殖过程中信号转导和转录活化因子-1（STAT1）的激活与核转位。方法 本文采用Western印迹、非同位素凝胶电泳（EMSA）和免疫荧光染色的方法，观察AngⅡ刺激大鼠主动脉VSMC前后，细胞中STAT1的活化状态与定位。结果 VSMC经AngⅡ干预后，胞内磷酸化的STAT1（P-STAT1）蛋白表达增加（P〈0．01），达峰后随时间梯度逐渐下降，AngⅡ干预15min后检测到胞核内有蛋白．DNA复合物形成。这一反应可被血管紧张素Ⅱ1型受体（AT1）阻滞剂Losartan以及Jak2抑制剂AC-490抑制（P〈0．01）。免疫荧光染色结果也显示AngⅡ干预后P-STAT1主要在胞核内表达。结论AngⅡ可以通过和AT1受体结合，激活Jak／STAT通路，在AngⅡ介导的大鼠VSMC增殖过程中发挥作用。     

骨桥蛋白参与血管紧张素Ⅱ诱导的血管平滑肌细胞迁移

目的检测血管紧张素Ⅱ(AngⅡ)对骨桥蛋白(OPN)表达的影响及其涉及的信号传导途径,并探讨OPN在AngⅡ诱导中膜平滑肌细胞(VSMCs)迁移中的作用。方法采用贴壁法培养SD大鼠胸主动脉的VSMCs。以免疫印迹(Western blot)法检测OPN表达。运用Transwell观察反义OPN在AngⅡ诱导的VSMCs迁移中的作用。结果(1)体外培养的大鼠VSMCs在基础状态下表达一定水平的OPN蛋白,经10-7mol/L AngⅡ诱导24 h后,OPN蛋白水平与对照组相比增加1.3倍(P<0.05);(2)预先给予AngⅡ1型(AT1)受体拮抗剂氯沙坦(losartan)、胞外信号调节激酶(ERK)抑制剂PD98059和P38丝裂原活化蛋白激酶(MAPK)抑制剂SB202190后,AngⅡ诱导的OPN的表达分别下降44.2%、23.6%及72.5%(P<0.05),而其2型(AT2)受体拮抗剂PD123319对OPN的表达没有影响。(3)反义OPN可以明显抑制AngⅡ诱导的VSMCs迁移(每个视野平均迁移细胞数目26.34±5.47 vs 50.23±6.12,P<0.05),而OPN正义、错配义组无此变化。结论(1)AngⅡ上调VSMCs中OPN的表达;(2)AT1受体、ERK和P38MAPK信号系统参与AngⅡ诱导的OPN表达。(3)OPN参与AngⅡ诱导的VSMCs迁移。     

比较替米沙坦与缬沙坦对人动脉平滑肌细胞增殖及血管紧张素Ⅱ受体表达的影响

目的 比较缬沙坦与替米沙坦对离体人主动脉平滑肌细胞(HASMCs)增殖及对血管紧张素受体表达的影响.方法 HASMCs 复苏、传代后,分别用不同浓度及条件的血管紧张素Ⅱ(AngⅡ)、缬沙坦(Val)、替米沙坦(Tel)、GW9662 干预HASMCs,采用CCK-8 检测细胞增殖能力,Western blot 方法检测细胞血管紧张素Ⅱ受体(AT)蛋白表达.结果 25 μmol/L Tel 与25 μmol/L Val 相比可更强地抑制1 μmol/L AngⅡ诱导的HASMCs 增殖.Tel 可抑制无AngⅡ刺激的HASMCs 增殖,且呈剂量依赖性,而Val 无此作用.25 μmol/L Tel 及Val 抑制HASMCs 上AT1受体表达相同(8.6%比17.0%,P>0.05),但Tel 促进AT2受体表达作用更强(29.9%比10.5%,P<0.05).氧化物酶体增殖体激活受体-γ(PPAR-γ)抑制剂GW9662 能抑制吡格列酮对HASMCs 抑制增殖的作用,但不能影响Tel 对HASMCs 抑制增殖作用.结论 替米沙坦比缬沙坦具有更强的抑制HASMCs 增殖及促进AT2受体表达上调的作用.     

Angiotensin II-triggered p44/42 mitogen-activated protein kinase mediates sympathetic excitation in heart failure rats

Angiotensin II (Ang II), acting via angiotensin type 1 receptors in the brain, activates the sympathetic nervous system in heart failure (HF). We reported recently that Ang II stimulates mitogen-activated protein kinase (MAPK) to upregulate brain angiotensin type 1 receptors in HF rats. In this study we tested the hypothesis that Ang II-activated MAPK signaling pathways contribute to sympathetic excitation in HF. Intracerebroventricular administration of PD98059 and UO126, 2 selective p44/42 MAPK inhibitors, induced significant decreases in mean arterial pressure, heart rate, and renal sympathetic nerve activity in HF rats, but had no effect on these variables in sham-operated rats. Pretreatment with losartan attenuated the effects of PD98059. Intracerebroventricular administration of the p38 MAPK inhibitor SB203580 and the c-Jun N-terminal kinase inhibitor SP600125 had no effect on mean arterial pressure, heart rate, or renal sympathetic nerve activity in HF. The phosphatidylinositol 3-kinase inhibitor LY294002 induced a small decrease in mean arterial pressure and heart rate but no change in renal sympathetic nerve activity. Immunofluorescent staining demonstrated increased p44/42 MAPK activity in neurons of the paraventricular nucleus of the hypothalamus of HF rats, colocalized with Fra-like activity (indicating chronic neuronal excitation). Intracerebroventricular PD98059 and UO126 reduced Fra-like activity in the paraventricular nucleus of the hypothalamus neurons in HF rats. In confirmatory acute studies, intracerebroventricular Ang II increased mean arterial pressure, heart rate, and renal sympathetic nerve activity in baroreceptor-denervated rats and Fra-like immunoreactivity in the paraventricular nucleus of the hypothalamus of neurally intact rats. Central administration of PD98059 markedly reduced these responses. These data demonstrate that intracellular p44/42 MAPK activity contributes to Ang II-induced neuronal excitation in the paraventricular nucleus of the hypothalamus and augmented sympathetic nerve activity in rats with HF.     

Chlamydia pneumoniae and chlamydial heat shock protein 60 stimulate proliferation of human vascular smooth muscle cells via toll-like receptor 4 and p44/p42 mitogen-activated protein kinase activation

An early component of atherogenesis is abnormal vascular smooth muscle cell (VSMC) proliferation. The presence of Chlamydia pneumoniae in many atherosclerotic lesions raises the possibility that this organism plays a causal role in atherogenesis. In this study, C pneumoniae elementary bodies (EBs) rapidly activated p44/p42 mitogen-activated protein kinases (MAPKs) and stimulated proliferation of VSMCs in vitro. Exposure of VSMCs derived from human saphenous vein to C pneumoniae EBs (3x10(7) inclusion forming units/mL) enhanced bromodeoxyuridine (BrdU) incorporation 12+/-3-fold. UV- and heat-inactivated C pneumoniae EBs also stimulated VSMC proliferation, indicating a role of direct stimulation by chlamydial antigens. However, the mitogenic activity of C pneumoniae was heat-labile, thus excluding a role of lipopolysaccharide. Chlamydial hsp60 (25 microg/mL) replicated the effect of C pneumoniae, stimulating BrdU incorporation 7+/-3-fold. Exposure to C pneumoniae or chlamydial hsp60 rapidly activated p44/p42 MAPK, within 5 to 10 minutes of exposure. In addition, PD98059 and U0126, which are two distinct inhibitors of upstream MAPK kinase 1/2 (MEK1/2), abolished the mitogenic effect of C pneumoniae and chlamydial hsp60. Toll-like receptors (TLRs) act as sensors for microbial antigens and can signal via the p44/p42 MAPK pathway. Human VSMCs were shown to express TLR4 mRNA and protein, and a TLR4 antagonist abolished chlamydial hsp60-induced VSMC proliferation and attenuated C pneumoniae-induced MAPK activation and VSMC proliferation. Together these results indicate that C pneumoniae and chlamydial hsp60 are potent inducers of human VSMC proliferation and that these effects are mediated, at least in part, by rapid TLR4-mediated activation of p44/p42 MAPK.     

Role of epidermal growth factor in pathogenesis of uterine leiomyomas

Objective:To investigate the role of epidermal growth factor(EGF) in the pathogenesis of uterine leiomyomas.Methods:Human myometrial smooth muscle cells(HM-SMCs) and smooth muscle cells of human uterine leiomyomas(HL-SMCs) were separated from patients' specimens and cultured.After processed by EGF or PD98059(inhibitor of MKK/MEK) +EGF,the proliferation rate of both SMCs was detected by BrdU method and the phosphorylation level of p44/42 mitogen-activated protein kinase(MAPK) was determined by Western-blot.After different processing time by EGF,the phosphorylation levels of p44/42 MAPK and AKT and p27 expression level in both SMCs were detected by Western-blot.Results:EGF could significantly promote HL-SMCs proliferation and PD98059 could inhibit this effect(P0.05);besides,PD98059 could inhibit the increase of the phosphorylation level of p44/42 MAPK in both SMCs induced by EGF.When the processing time by EGF was over 15 min,the phosphorylation levels of p44/42 MAPK and AKT in both SMCs decreased sharply and were close to zero:p27 expression in HM-SMCs raised significantly while the upregulation in HL-SMCs was little.Conclusions:EGF could not cause activation of EGFR because of the dephosphorylation of p44/42 MAPK and AKT in HL-SMCs,which caused p27 expression insufficiently and cell cycle dysregulation.     

Mitogen-activated protein kinases mediate upregulation of hypothalamic angiotensin II type 1 receptors in heart failure rats

In heart failure (HF), angiotensin II type 1 receptor (AT(1)-R) expression is upregulated in brain regions regulating sympathetic drive, blood pressure, and body fluid homeostasis. However, the mechanism by which brain AT(1)-R are upregulated in HF remains unknown. The present study examined the hypothesis that the angiotensin II (Ang II)-triggered mitogen-activated protein kinases (MAPKs) p44/42, p38, and c-Jun N-terminal kinase contribute to upregulation of the AT(1)-R in the hypothalamus of rats with HF. AT(1)-R protein, AT(1)-R mRNA, and AT(1)-R immunoreactivity increased in the paraventricular nucleus of hypothalamus and the subfornical organ of rats with ischemia-induced HF compared with sham-operated controls. Phosphorylated p44/42 MAPK, c-Jun N-terminal kinase, and p38 MAPK also increased in paraventricular nucleus and subfornical organ. A 4-week ICV infusion of the AT(1)-R antagonist losartan decreased AT(1)-R protein and phosphorylation of p44/42 MAPK, c-Jun N-terminal kinase, and p38 MAPK in the HF rats. A 4-week ICV infusion of the p44/42 MAPK inhibitor PD98059 or the c-Jun N-terminal kinase inhibitor SP600125 significantly decreased AT(1)-R protein and AT(1)-R immunoreactivity in the paraventricular nucleus and subfornical organ, but the p38 MAPK inhibitor SB203580 did not. Treatment with ICV losartan, PD98059, and SP600125 had no effect on AT(1)-R expression by Western blot in sham-operated rats. In untreated HF rats 4 weeks after coronary ligation, a 3-hour ICV infusion of PD98059, SP600125, or losartan reduced AT(1)-R mRNA in paraventricular nucleus and subfornical organ. These data indicate that MAPK plays an important role in the upregulation of AT(1)-R in the rat forebrain in HF and suggest that Ang II upregulates its own receptor by this mechanism.     

p38MAPK inhibition enhances basal and norepinephrine-stimulated p42/44MAPK phosphorylation in rat pinealocytes

Interaction between p38MAPK and p42/44MAPK in rat pinealocytes was examined by determining the effects of p38MAPK inhibitors on the phosphorylation of p42/44MAPK using Western blot analysis. Treatment with SB202190, a specific inhibitor of p38MAPK, increased p42/44MAPK phosphorylation in a concentration-dependent manner. SB202190 also enhanced the magnitude and the duration of norepinephrine-activated p42/44MAPK phosphorylation. The effect of SB202190 on p42/44MAPK phosphorylation was abolished by PD98059 or UO126, inhibitors of MEK, suggesting that SB202190 is acting upstream of MEK in activating p42/44MAPK. The SB202190-induced phosphorylation of p42/44MAPK was not blocked by inhibitors of cGMP-dependent kinase (KT5823), protein kinase C (calphostin C) or Ca2+/calmodulin dependent kinase (KN93) suggesting that these pathways may not be involved in the effect of SB202190. SB202190 further increased p42/44MAPK phosphorylation that was stimulated by 8-bromo-cGMP, 4beta phorbol 12-myristate 13-acetate, or ionomycin. In contrast, inhibition of p42/44MAPK phosphorylation by dibutyryl-cAMP persisted when p42/44MAPK phosphorylation was increased by SB202190. Furthermore, inhibition of p42/44MAPK phosphorylation had no effect on p38MAPK activation. These results suggest that inhibition of p38MAPK causes activation of p42/44MAPK and acts synergistically with norepinephrine in the regulation of p42/44MAPK activation in rat pinealocytes.     

The inhibitory mechanisms of amlodipine in human vascular smooth muscle cell proliferation.

The abnormal proliferation of vascular smooth muscle cells (VSMCs) is closely related to vascular diseases. There is growing evidence that calcium antagonists inhibit VSMC growth/proliferation, yet their molecular mechanisms remain to be determined. Recent reports suggest that p42/p44 mitogen-activated protein kinases (MAPKs) play an important role in cell growth and proliferation induced by growth factors. This study was designed to determine whether these MAPKs are involved in VSMC proliferation induced by basic fibroblast growth factor (bFGF) and to examine the inhibitory effect of amlodipine. Human VSMCs were obtained from inner mammary artery. p42/p44 MAPKs activity was measured by immunoblotting assay using anti-p42/p44 phospho-MAPK antibody. 1) bFGF (20 ng/ml) significantly activated p42/p44 MAPKs with a peak time of 5-15 min, which was maintained for 3 h. PD98059 (100 nM-10 microM), a specific inhibitor of MAPK kinase, inhibited bFGF-induced p42/p44 MAPKs activation in a dose-dependent manner. 2) Amlodipine (1-100 nM) dose-dependently inhibited p42/p44 MAPKs activation by bFGF. 3) Amlodipine (10 nM) could inhibit both short-term and long-term p42/p44 MAPKs activation by bFGF. Our results indicate that bFGF could activate p42/p44 MAPKs. Amlodipine, which could inhibit bFGF-induced human VSMC proliferation, inhibited both short-term and sustained p42/p44 MAPKs activation by bFGF, suggesting that bFGF-induced VSMC proliferation may be related to p42/p44 MAPKs activation, and that the antiproliferative effect of amlodipine may be related to its inhibition of p42/p44 MAPKs activation.