丹参酮ⅡA磺酸钠对血管紧张素Ⅱ诱导的心肌肥大及p-ERK表达的影响

目的：观察丹参酮ⅡA磺酸钠（STS）对血管紧张素Ⅱ（AngⅡ）诱导的心肌肥大及p-ERK表达的影响。方法：培养新生大鼠心肌细胞，考马斯亮蓝法测定心肌细胞蛋白含量、[H^3]-亮氨酸掺入法测定蛋白合成速率作为心肌肥大指标；用West—ern-blot测定p-ERK表达。结果：STS能显著降低AngⅡ诱导的心肌细胞总蛋白含量、蛋白合成速率上升，同时对p-ERK表达具有剂量、时间依赖性抑制作用。结论：STS可以抑制AngⅡ诱导的心肌肥大，机制与抑制p-ERK表达有关。     

丹参酮ⅡA磺酸钠对AngⅡ诱导的心肌细胞肥大反应中磷酸化细胞外信号调节激酶1/2的作用

目的从细胞外信号调节激酶1/2(ERK1/2)激活角度研究丹参酮ⅡA磺酸钠(sodium tanshinoneⅡ Asulfonate,STS)对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导的心肌肥大反应中的作用。方法培养新生大鼠心肌细胞,考马斯亮蓝法测定心肌细胞蛋白含量、[3H]-亮氨酸参入法测定蛋白合成速率作为心肌肥大指标;用免疫荧光标记法和Western blot测定磷酸化ERK1/2蛋白(p-ERK1/2)表达。结果(1)AngⅡ(1μmol·L-1)处理24h,心肌细胞[3H]-亮氨酸参入率、蛋白含量明显增加,STS能明显抑制AngⅡ介导心肌细胞[3H]-亮氨酸参入率、蛋白含量的增加;(2)AngⅡ刺激心肌细胞可见胞核内出现磷酸化ERK1/2荧光染色,丹参酮ⅡA可阻断AngⅡ引起的ERK1/2活化、入核过程;(3)用AngⅡ(1μmol·L-1)处理心肌细胞5min,磷酸化ERK1/2蛋白(p-ERK1/2)表达即开始增加,10min左右时最明显。以AngⅡ(1μmol·L-1)处理心肌细胞10min,磷酸化ERK1/2蛋白(p-ERK1/2)表达为标准,预先以STS(2,10,50μmol·L-1)处理心肌细胞30min,发现STS可明显抑制AngⅡ诱导的心肌细胞磷酸化ERK1/2蛋白表达;(4)预先以不同浓度STS处理心肌细胞30min,发现STS对AngⅡ诱导的心肌细胞磷酸化ERK1/2蛋白表达的抑制作用存在剂量依赖性。结论STS可以抑制AngⅡ诱导的心肌肥厚,其机制与抑制磷酸化ERK1/2表达有关。     

粉防己碱对血管紧张肽II诱导心肌肥大以及p-ERK1/2表达的影响

目的 观察粉防己碱(tetrandrine, Tet)对血管紧张肽Ⅱ(angiotensinⅡ, Ang Ⅱ)诱导的心肌肥大及p-ERK1/2表达的影响. 方法 培养新生大鼠心肌细胞, 免疫荧光法测定心肌细胞体积、［³H］-亮氨酸掺入法测定蛋白合成速率作为心肌肥大指标;以ERK免疫沉淀活性试剂盒测定ERK活性, Western-blot测定p-ERK1/2表达. 结果Tet能显著抑制Ang Ⅱ诱导的心肌细胞体积、蛋白合成速率的上升;对p-ERK1/2表达及活性具有剂量依赖性的抑制作用. 结论Tet可以明显抑制Ang Ⅱ诱导的心肌肥大, 可能与其降低p-ERK1/2表达及活性有关.     

姜黄素通过激活ATRAP信号通路抑制血管紧张素Ⅱ诱导的心肌肥大

目的探究姜黄素抑制血管紧张素Ⅱ(AngⅡ)诱导的心肌肥厚相关病理机制。方法 MTT法和乳酸脱氢酶试剂盒检测姜黄素的心肌细胞毒性;200 nmol·L~(-1) AngⅡ孵育心肌细胞24 h诱导心肌肥厚;α-actinin染色观察心肌细胞形态大小;q PCR检测心肌肥大标记物ANF、BNP、β-MHC的m RNA水平;通过Western blot检测AngⅡ受体的抑制蛋白ATRAP的表达情况。结果姜黄素对心肌细胞无明显毒性;200 nmol·L~(-1)的AngⅡ刺激心肌细胞24 h显著诱导心肌细胞肥大;ANP、BNP、β-MHC的m RNA水平显著增高;AngⅡ受体的抑制蛋白ATRAP表达明显降低;姜黄素预作用细胞1 h显著抑制AngⅡ诱导的心肌肥大,逆转AngⅡ降低的ATRAP表达。结论姜黄素抑制AngⅡ诱导的心肌肥大可能与其激活ATRAP信号通路有关。     

丹参酮ⅡA抑制血管紧张素Ⅱ诱导的大鼠心肌细胞肥大

目的　在原代培养的新生大鼠心肌细胞上 ,观察丹参酮ⅡA(TSN)对血管紧张素Ⅱ (AngⅡ )诱导的心肌细胞肥大的影响。方法　采用3 H -亮氨酸掺入法测定心肌细胞蛋白质合成速率 ,作为心肌细胞肥大的指标 ;用逆转录聚合酶链式反应检测心肌细胞原癌基因c -fosmRNA的表达。结果　TSN能抑制AngⅡ诱导的大鼠心肌细胞蛋白质合成的增加 (P <0 .0 5 )及心肌细胞原癌基因c -fosmRNA表达的增强 (P <0 .0 5 ) ,其效果与AngⅡ受体阻滞剂缬沙坦相似。结论　TSN可以抑制AngⅡ诱导的大鼠心肌细胞肥大 ,这与其抑制了原癌基因c-fos的表达有关。     

荞麦花叶中芦丁对血管紧张素Ⅱ诱导的新生大鼠心肌细胞肥大的体外抑制作用

目的 观察荞麦花叶中芦丁(RBFL)对新生大鼠心肌细胞肥大的作用,并探讨其对蛋白激酶C(PKC)信号途径的影响.方法 选用培养的新生大鼠心肌细胞为研究对象,以10-7mol·L-1血管紧张素Ⅱ(AngⅡ)刺激建立体外心肌细胞肥大模型,并用不同浓度的RBFL作用于细胞,测定心肌细胞表面积,3H-亮氨酸掺入法测定心肌细胞蛋白质的合成速率,免疫细胞化学法测定心肌细胞PKC蛋白的表达,同位素底物掺入法检测PKC活性.结果 10-7mol·L-1AngⅡ能显著增加心肌细胞表面积和蛋白质合成速率、PKC蛋白的表达及其活性;1～10 mg·L-1RBFL能剂量依赖性地抑制AngⅡ诱导的心肌细胞表面积和蛋白质合成速率的增加、PKC蛋白的表达及其活性,并具有统计学意义.结论 RBFL能明显抑制培养的新生大鼠心肌细胞的肥大,此作用可能与其对心肌细胞中PKC信号途径的调控有关.     

熊果酸对血管紧张肽Ⅱ诱导心肌成纤维细胞增殖及胶原合成的影响

［摘要］目的观察熊果酸对血管紧张肽II（ Ang Ⅱ）诱导心肌成纤维细胞增殖及胶原合成的影响。方法培养新生大鼠心肌成纤维细胞,噻唑蓝（MTT）法测定细胞增殖,羟脯氨酸法检测胶原含量,［3H］ 脯氨酸掺入法测定胶原合成速率,免疫荧光法观察成纤维细胞形态学改变。Western blot测定还原型辅酶II（NADPH）亚单位p47 phox蛋白表达。结果Ang Ⅱ能够明显上调心肌成纤维细胞增殖、胶原含量、胶原合成速率及p47 phox表达。经熊果酸处理后,以上指标均明显下调。结论熊果酸能减轻Ang Ⅱ诱导心肌成纤维细胞增殖、胶原分泌及合成速率,机制与抑制p47 phox通路有关。     

丙泊酚对血管紧张肽Ⅱ诱导心肌细胞肥大及ROS/JNK1/2通路的影响

目的 探讨丙泊酚对血管紧张肽Ⅱ(angiotensin Ⅱ, Ang Ⅱ)诱导的心肌细胞肥大及活性氧(ROS)/ 活化c-Jun氨基末端激酶(c-Jun N-teminal kinase1/2, JNK1/2)通路的影响. 方法 培养1～2 d龄乳鼠心肌细胞,相差显微镜观察心肌细胞直径、[³H] 亮氨酸掺入法测定蛋白合成速率作为心肌肥大指标;细胞内ROS水平用ROS敏感的荧光探针2,7 dichlorofluorescein diacetate(DCFH-DA)反映. 比色法测定NADPH氧化酶(NADPH oxidase, Nox)活性. 免疫印记法测定JNK1/2磷酸化水平. 结果 Ang Ⅱ能显著提高心肌细胞直径、蛋白合成速率、Nox活性及ROS水平,并明显促进JNK1/2磷酸化,以上效应被不同浓度丙泊酚所抑制. 结论丙泊酚可抑制Ang Ⅱ诱导的乳鼠心肌细胞肥大,其机制可能与下调ROS/JNK1/2通路有关.     

碘化N-正丁基氟哌啶醇对血管紧张素Ⅱ诱导心肌细胞肥大的抑制作用

目的探讨碘化N-正丁基氟哌啶醇(F2)对血管紧张素Ⅱ(AngII)诱导心肌细胞肥大的抑制作用及其机制。方法培养大鼠心肌细胞株(H9C2细胞),测量细胞表面积和BCA法测定细胞蛋白含量作为心肌肥大指标;Western blot检测核转录因子ERK1/2及CREB蛋白表达。结果 (1)AngII(10-7mol.L-1)处理细胞48 h,心肌细胞表面积增大,蛋白含量明显增加,F2(10-8、10-7、10-6mol.L-1)剂量依赖抑制AngII介导心肌细胞表面积的增大以及蛋白含量的增加;(2)AngII(10-7mol.L-1)处理心肌细胞1 min,磷酸化ERK1/2蛋白(p-ERK1/2)和磷酸化CREB蛋白(p-CREB)表达即开始增加,5～10 min达最高峰,可持续活化60 min,ERK1/2和CREB蛋白总量没有变化。以AngII处理心肌细胞5 min,p-ERK1/2和p-CREB表达为标准,预先以F2(10-8、10-7、10-6mol.L-1)处理心肌细胞30 min,F2剂量依赖抑制AngII介导心肌细胞p-ERK1/2和p-CREB表达的增高。结论 F2可以抑制AngII诱导的心肌肥大,其机制可能与抑制磷酸化ERK1/2和CREB表达有关。     

腺苷对肿瘤坏死因子-α诱导乳鼠心肌细胞肥大及核因子-κB的影响

目的探讨腺苷对肿瘤坏死因子-α(tumor necrosis fac-tor,TNF-α)诱导心肌细胞肥大及核因子-κB(NF-κB)表达的影响。方法以原代培养乳鼠心肌细胞为模型,应用TNF-α100μg.L-1诱导心肌细胞肥大,观察不同浓度腺苷对心肌肥大的影响。用考马斯亮蓝法测定心肌细胞蛋白含量;RT-PCR检测心肌细胞心钠素(atrial natriuretic peptide,ANP)mRNA的表达;Western blot法检测心肌细胞p65和IκBα的蛋白含量;ELISA法检测细胞外液白介素-1β(IL-1β)的含量。结果腺苷能够有效抑制TNF-α诱导的心肌肥大,表现为蛋白含量减少,ANPmRNA表达降低,并且能抑制TNF-α诱导的NF-κB活化,表现为细胞内p65蛋白表达减少,IκBα蛋白表达增加和细胞外液IL-1β表达降低。结论腺苷对TNF-α诱导的心肌肥大有保护作用,可能与腺苷抑制心肌细胞NF-κB活化有关。     

Inhibitory effect of antisense oligodeoxynucleotide to p44／p42 MAPK on angiotensin II-induced hypertrophic response in cultured neonatal rat cardiac myocyte

AIM: To explore the inhibitory effect of antisense oligonucleotide (ODN) to mitogen activated protein kinase(MAPK) on cardiomyocyte hypertrophy induced by angiotensin Ⅱ (Ang Ⅱ). METHODS: A 17-mer phosphorothioate-protected antisense ODN directed against the initiation of translation sites of the p42 and p44 MAPK isoforms byliposomal transfection was applied to inhibit the translation of p44/p42 MAPK mRNA. The sense and random ODNs to p44/p42MAPK were used as sequence controls. Neonatal cardiac myocytes were exposed to Ang Ⅱ (10nmol/L) for 5 min and then harvested in lysis buffer for the measurement of the activity and the phosphorylated protein content of p44/p42MAPK that were tested by P-81 phosphocellulose filter paper method and Western blotting, respectively. The rate of protein synthesis by [^3H]leucine incorporation and the diameter of cell were measured after exposure to Ang Ⅱ for 24 h and 72 h, respectively. RESULTS: In cardiac myocyte Ang Ⅱ increased p44/p42MAPK activity and phosphorylated protein content by 140 % and 699 %, and also increased [^3H]leucine incorporation and cell diameter by 40 % and 27 %. c-fos and c-myc mRNAs were induced significantly after exposure to Ang Ⅱ. Antisense ODN to p44/p42MAPK (0.2 μmol/L) reduced Ang Ⅱ-induced MAPK activity by 30 %,and phophorylated MAPK protein expression by 59 % in cardiac myocyte, and inhibited c-fos and c-myc mRNA expression induced by Ang Ⅱ by 44 % and 43 %, respectively. The diameter and the rate of protein synthesis of cardiac myocyte induced by Ang Ⅱ were decreased by 16 % and 22 % after pretreatment with antisense ODN to p44/p42MAPK. CONCLUSION: Antisense ODN to p44/p42 MAPK inhibited the increase of rate of protein synthesis,and the augmentation of cell diameter and expression of c-fos and c-myc mRNA induced by Ang Ⅱ in culturedcardiac myocytes, p44/p42 MAPK played a critical role in the hypertrophic response induced by Ang Ⅱ in cultured neonatal rat cardiac myocytes.     

丹参酮ⅡA对AngⅡ诱导的心肌肥大中c-fos、c-myc和c-jun mRNA表达的影响

目的在原代培养的新生大鼠心肌细胞上,观察丹参酮ⅡA(tanshinoneⅡ,TSN)对血管紧张素Ⅱ(angiotensinⅡA,AngⅡ)诱导的心肌细胞肥大的影响。方法实验用新生大鼠,差数贴壁法体外分离培养大鼠心肌细胞。用血管紧张素Ⅱ诱导心肌细胞肥大,丹参酮ⅡA和缬沙坦(valsartan)进行干预;采用相差显微镜测量细胞大小;测定心肌细胞3H-亮氨酸参入作为心肌细胞肥大的指标;用逆转录聚合酶链式反应(RT-PCR)检测心肌细胞原癌基因c-fos、c-myc和c-junmR-NA的表达;MTT法检测细胞活力。结果用MTT法检测发现,培养的心肌细胞中加入TSN(5~80μmol·L-1),24h后会产生微弱的细胞毒性,但心肌细胞单层在TSN存在的情况下可以继续同步收缩。在AngⅡ持续作用7d后,血管紧张素Ⅱ组心肌细胞直径增大(28·5±3·8)μm,与对照组(19·8±1·9)μm相比差异有显著性(P<0·05);TSN抑制AngⅡ介导的心肌细胞直径增大(21·3±2·5)μm,与AngⅡ组相比差异有显著性(P<0·05),AngⅡ作用24h后,心肌细胞合成速率AngⅡ组(1900±100)cpm较对照组(1205±129)cpm明显增加(P<0·01),TSN和valsartan本身对心肌细胞蛋白质的合成没有影响,但均能抑制AngⅡ刺激的心肌细胞蛋白质合成速率的增加(P<0·01)。在培养液中加入AngⅡ作用30min后,c-fos、c-myc和c-junmRNA的表达明显增强(P<0·01),预先加入TSN或valsartan作用30min,可阻断AngⅡ的作用(P<0·01),而TSN和valsartan本身对原癌基因c-fos、c-myc和c-junmRNA的表达无影响。结论TSN可以抑制AngⅡ诱导的心肌细胞肥大,这可能与其抑制了原癌基因c-fos、c-myc和c-jun的表达有关。     

Dopamine D2 receptor stimulation inhibits angiotensin II-induced hypertrophy in cultured neonatal rat ventricular myocytes

1. Myocardial hypertrophy is a common pathological change that accompanies cardiovascular disease. Dopamine D2 receptors have been demonstrated in cardiovascular tissues. However, the pathophysiological involvement of D2 receptors in myocardial hypertrophy is unclear. Therefore, the effects of the D2 receptor agonist bromocriptine and the D2 receptor antagonist haloperidol on angiotensin (Ang) II- or endothelin (ET)-1-induced hypertrophy of cultured neonatal rat ventricular myocytes were investigated in the present study. 2. Protein content and protein synthesis, determined by examining [(3)H]-leucine uptake, were used as estimates of cardiomyocyte hypertrophy. The expression of D2 receptor protein in neonatal rat ventricular myocytes was determined using western blotting. Changes in [Ca(2+)](i) in cardiomyocytes were observed by laser scanning confocal microscopy. 3. Angiotensin II and ET-1, both at 10 nmol/L, induced myocyte hypertrophy, as demonstrated by increased protein content and synthesis, [Ca(2+)](i) levels, protein kinase C (PKC) activity and phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase and mitogen-activated protein kinase (MAPK) p38 (p38). Concomitant treatment of cells with 10 nmol/L AngII plus 10 micromol/L bromocriptine significantly inhibited cardiomyocyte hypertrophy, MAPK phosphorylation and PKC activity in the membrane, as well as [Ca(2+)](i) signalling pathways, compared with the effects of AngII alone. In addition, 10 micromol/L bromocriptine significantly inhibited cardiomyocyte hypertrophy induced by 10 nmol/L ET-1. However, pretreatment with haloperidol (10 micromol/L) had no significant effects on cardiomyocyte hypertrophy induced by either AngII or ET-1. 4. In conclusion, D2 receptor stimulation inhibits AngII-induced hypertrophy of cultured neonatal rat ventricular myocytes via inhibition of MAPK, PKC and [Ca(2+)](i) signalling pathways.     

Inhibitory effects of Veratrum nigrum L. Var. ussurience Nakai alkaloids on the hypertrophy of cardiomyocytes from neonatal rat

Objective To examine the effects of Veratrum nigrum L.Var.ussurience Nakai alkaloids(VnA)on angiotensin Ⅱ(AngⅡ)-induced cardiomyocyte hypertrophy and to explore its possible mechanism.Methods The cadiocytes were induced by AngⅡ to set up myocardial hypertrophy model,the animals were divided into six groups according to the different treatments:control group,model group,positive control group,VnA group(low,middle and high dose).The cell protein content,the cell diameter and the expression of calcineurin(CaN)were measured respectively by BCA method,the micrometer and immunofluorescence analysis.Results VnA(middle and high dose)and Captopril inhibited significantly the increase in the protein content induced by AngⅡ(P<0.01).VnA and Captopril inhibited significantly the increase in the diameters induced by AngⅡ(P<0.01).By immunofluorescence analysis,the expression of calcineurin(CaN)was obviously increased in the AngⅡ-induced model group.VnA decreased the expression of CaN significantly.Conclusions VnA could inhibit the cardiomyocyte hypertrophy induced by AngⅡ significantly in a dose-dependent manner.The possible mechanism may be related to the inhibition of CaN expression.     

NO在非诺贝特抗血管紧张素Ⅳ所致心肌肥大中的作用

目的研究非诺贝特(fenofibrate,FF)抗血管紧张Ⅳ(angiotensinⅣ,AngⅣ)所致心肌细胞肥大作用及其机制。方法利用乳鼠心肌细胞培养,以细胞表面积、蛋白含量和心房利钠因子mRNA表达为肥大指标,观察FF对AngⅣ诱导心肌肥大的作用。Real-time PCR和Western blot方法检测mRNA及蛋白水平的表达;比色法和硝酸还原法分别检测一氧化氮合酶(nitric oxide synthase,NOS)活性和一氧化氮(ni-tric oxide,NO)浓度。结果 AngⅣ诱导心肌细胞肥大(P<0.01);FF浓度依赖性地抑制AngⅣ的作用(P<0.01);FF0.3μmol.L-1明显上调AngⅣ导致的过氧化物酶体增殖物激活受体-α(peroxisome proliferator-activated receptor-α,PPAR-α)以及内皮型NOS mRNA和蛋白表达的降低(P<0.01),同时增加NOS活性和NO浓度(P<0.01)。PPAR-α阻断剂MK886可完全取消FF的上述作用(P<0.05)。L-精氨酸的作用与FF相似(P<0.01),NOS阻断剂NG-硝基-L-精氨酸-甲酯可完全取消其作用(P<0.01)。结论 FF可能通过激活其特异性受体PPAR-α,上调NOS表达,促进NO释放,最终产生抗AngⅣ诱导心肌肥大的作用。     

Antagonism of the renin-angiotensin system, hypertrophy and gene expression in cardiac myocytes.

In response to humoral and mechanical stimuli, the myocardium adapts to increased work load through hypertrophy of individual muscle cells. Myocardial hypertrophy is characterized by an increase in cell size in the absence of cell division and is accompanied by changes in gene expression. Angiotensin II (Ang II), the effector peptide of the renin-angiotensin system (RAS), regulates volume and electrolyte homeostasis and is involved in cardiac and vascular growth in rats. In this review, the role of RAS in myocyte protein synthesis (myocyte hypertrophy) and in induction of gene expression will be discussed in rat cardiomyocytes in culture. Traditional RAS can be considered as a system in which circulating Ang II is delivered to target tissues or cells. However, a local RAS has also been described in cardiac cells and evidence has been accumulated for autocrine and/or paracrine pathways by which biological actions of Ang II can be mediated. These actions of Ang II are primarily mediated through Ang II receptors subtype I (AT1-R). When evaluating the effects of Ang II in situ, both changes in circulating levels and local production have to be taken into account. Contrasting results have been found concerning the in vitro effect of Ang II on the protein synthesis in cardiac myocytes and can be at least partly be attributed to methodological problems such as assay of de novo protein synthesis and isolation and separation procedure of cardiac myocytes. The Ang II-induced hypertrophic effect also depends on the existence of nonmyocytes in a cardiocyte culture. In rat cardiocytes, AngII also causes induction of many immediately-early genes (c-fos, c-jun, jun-B, Egr-1 and c-myc) and induces also late markers of cardiac hypertrophy (skeletal alpha-actin and atrial natriuretic peptide expression) and growth factors (TGF-beta 1 gene expression). In vivo AngII via AT1-R, causes not only ventricular hypertrophy but also a shift to the fetal phenotype of the myocardium. Angiotensin-converting enzyme inhibitors and AngII receptor antagonists of the subtype I not only induce the regression but also prevent the development of cardiac hypertrophy in experimental rat models.     

尿促皮素诱导乳大鼠心肌细胞肥大的作用及信号传导机制

目的探讨尿促皮素(urocortin)诱导大鼠心肌细胞肥大的作用及其信号传导机制。方法实验分8组,正常对照组、尿促皮素0.1μmol.L-1组、星形孢菌素(Sta)1μmo.lL-1、H890.1μmol.L-1和维拉帕米(Ver)1μmol.L-1组及尿促皮素分别加Sta,H89和Ver组。采用体外培养的乳大鼠心肌细胞,应用尿促皮素0.1μmol.L-1诱导心肌肥大,观察Sta1μmol.L-1,H890.1μmo.lL-1和Ver1μmol.L-1的作用,进一步探讨尿促皮素0.1μmol.L-1诱导心肌肥厚的作用机制。用消化分离法及计算机图像分析系统检测心肌细胞直径;[3H]亮氨酸掺入法测定心肌细胞蛋白质的合成;用Lowry法检测心肌细胞蛋白质含量;用Western蛋白印迹法测定心房钠尿肽(ANP)表达;采用Till阳离子测定系统,以Fura-2/AM为荧光探针,观察心肌细胞[Ca2+]i瞬间变化。结果尿促皮素使心肌细胞直径、蛋白质合成、蛋白质含量和ANP表达分别增加30.9%,36.3%,35.5%和34.7%;尿促皮素+Sta组使心肌细胞直径、蛋白质合成、蛋白质含量和ANP表达分别降低了16.5%,22.1%,18.1%和21.3%;尿促皮素+H89组使心肌细胞直径、蛋白质合成、蛋白质含量和ANP表达分别降低了16.6%,21.5%,19.5%和20.6%;尿促皮素+Ver组使心肌细胞直径、蛋白质合成、蛋白质含量和ANP表达分别降低了17.1%,20.9%,17.9%及19.9%;尿促皮素能够使心肌细胞[Ca2+]i瞬间变化水平增高,Sta,H89和Ver能够降低尿促皮素引起的心肌细胞[Ca2+]i瞬间变化升高。结论尿促皮素可能通过蛋白激酶C和蛋白激酶A信号途径影响L-型Ca2+通道,进而影响细胞[Ca2+]i瞬间变化水平,诱导乳大鼠心肌细胞肥大。     

黄芪苷Ⅳ对血管紧张素Ⅱ诱导新生大鼠心肌细胞肥大的保护作用

目的研究黄芪苷Ⅳ(astragalosideⅣ,AST)对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导新生大鼠心肌细胞肥大的保护作用并探讨其作用机制。方法AngⅡ刺激新生大鼠心肌细胞,制备心肌细胞肥大模型,分别用AST10mg·mL-1和20mg·mL-1进行预防性治疗。检测心肌细胞直径及细胞总蛋白含量,测定心肌细胞[Ca2+]i、肌浆网钙泵(SERCA)活力和钙调神经磷酸酶(CaN)活性。结果AngⅡ组细胞直径增大,总蛋白含量增加,与对照组相比差异有显著性(P<0.01);AST10mg·mL-1和20mg·mL-1能够降低心肌细胞肥大程度(P<0.05或P<0.01)、[Ca2+]i(P<0.01)及CaN活性(P<0.05或P<0.01)、提高SERCA活力(P<0.01)。结论AST对AngⅡ诱导心肌细胞肥大有明显的保护作用,可能与其降低[Ca2+]i、提高心肌SERCA活力及降低CaN活性有关。