灯盏花素对异丙肾上腺素引起大鼠心肌肥厚和纤维化的保护作用

目的研究灯盏花素(breviscapine,Bre)对异丙肾上腺素引起大鼠心肌肥厚和纤维化的保护作用及其机制。方法用异丙肾上腺素(isoproterenol,Iso)皮下注射,连续7d,建立大鼠心肌肥厚和纤维化模型。造模d2起给大鼠腹腔注射Bre12.5和25mg·kg-1·d-1,连续用药14d,测量大鼠心脏重量指数(HW/BW)和左心室重量指数(LVW/BW),放射免疫分析法检测左心室心肌组织中血管紧张素Ⅱ(AngⅡ)的变化;分光光度法检测左心室心肌组织中羟脯氨酸、一氧化氮(NO)含量和Na+,K+ATPase,Ca2+ATPase活性。结果Iso模型组大鼠心重指数和左心室重量指数明显增大,左心室心肌组织中AngⅡ和羟脯氨酸含量增高,NO水平下降,Na+,K+ATPase和Ca2+ATPase活力下降,Bre能提高心肌组织中的NO含量,抑制AngⅡ产生,增强Na+,K+ATPase和Ca2+ATPase活力,降低羟脯氨酸含量,抑制胶原的产生。结论Bre对Iso引起大鼠心肌肥厚和纤维化具有一定的改善作用。     

映山红花总黄酮对盐酸异丙肾上腺素诱导大鼠心肌缺血的保护作用

目的观察映山红花总黄酮(TFR)对盐酸异丙肾上腺素诱导的实验性心肌缺血的保护作用。方法采用皮下(sc)注射盐酸异丙肾上腺素(Iso)(8 mg·kg^-1×2 d)诱导大鼠实验性心肌缺血模型,测定血清中MDA含量、GSH-PX活力、SOD及心肌组织中ATPase活性。同时行心肌组织病理组织学检查。结果TFR 30 mg·kg^-1显著降低血清中MDA的生成,30,15 mg·kg^-1及60,30 mg·kg^-1升高SOD,GSH-PX的活力,60,30 mg·kg^-1TFR可抑制心肌组织中Na⁺-K⁺-ATPase,Ca²⁺-Mg²⁺-AT-Pase,总ATPase活力的降低,TFR 60,30 mg·kg^-1能显著改善sc Iso后心肌病理损伤程度,降低其病理损伤评分。结论TFR对盐酸异丙肾上腺素诱导的实验性心肌缺血有保护作用,其机制可能与减少体内自由基生成、改善心肌能量代谢有关。     

阿米洛利对压力超负荷心肌肥厚大鼠心肌细胞内游离钙的影响

目的:观察阿米洛利预防性给药对压力超负荷心肌肥厚大鼠心肌细胞[Ca²⁺]i 影响。方法:以Fura-2/AM为指示剂,测定单细胞[Ca²⁺]i。结果:压力超负荷大鼠左室心肌细胞[Ca²⁺]i 升高,阿米洛利和依那普利组则[Ca²⁺]i 明显降低。给予KCl,NE刺激后,给药组左室心肌细胞[Ca²⁺]i 的增加值明显低于左室肥厚组,百日咳毒素(PTX,100 ng·L^-1) 处理5 h 后,其静息[Ca²⁺]i 无显著变化,但抑制NE诱导左室心肌细胞[Ca²⁺]i 升高,该作用在左室肥厚组更明显,对KCl 刺激引起的[Ca²⁺]i 升高,给药组无影响,左室肥厚组的升高值略有增加。结论:NE所致心肌细胞[Ca₂₊]i 升高与PTX敏感的G 蛋白有关,肥厚时此途径亢进。     

西红花酸对去甲肾上腺素所致原代培养心肌细胞能量代谢和凋亡的影响

目的研究西红花酸对去甲肾上腺素(NE)诱导原代培养心肌细胞能量代谢障碍和细胞凋亡的保护作用。方法1 μmol·L^-1 NE损伤原代培养的心肌细胞,检测细胞培养上清液的LDH、心肌细胞ATPase、线粒体琥珀酸脱氢酶(MSDH)的活力,线粒体膜电位的变化,流式细胞仪检测细胞凋亡,观察西红花酸保护作用。结果模型组细胞培养上清液LDH增加,心肌细胞MSDH和ATPase的活力降低,线粒体膜电位降低,心肌细胞凋亡率增加。西红花酸明显降低培养上清液LDH增加,提高MSDH和ATPase的活力、线粒体膜电位的水平,对心肌细胞的凋亡具有明显的保护作用。结论西红花酸对NE所致的心肌细胞能量代谢障碍和凋亡具有明显的保护作用。     

阿米洛利对大鼠压力超负荷性心肌肥厚的抑制作用

目的　观察钠氢交换体(NHE)抑制剂阿米洛利(Ami)对压力超负荷左室肥厚(LVH)大鼠心功能、心肌细胞内游离钙浓度([Ca²⁺]_i)及心肌细胞膜Na⁺ 、K⁺-ATP酶活性的影响。方法　①同步记录离体工作心脏LVSP、LVEDP、±dp/dt_max及T值;②测定Fura-2/A负载后的单个心室肌细胞的[Ca²⁺]_i;③光电比     

粉防己碱对离体大鼠心脏钙反常的保护作用

粉防己碱(Tet)能明显抑制离体大鼠心脏钙反常时心肌组织LDH和蛋白的释出,减少无钙灌流时心肌组织Ca²⁺丢失和Na⁺堆积以及复钙灌流时心肌组织Ca²⁺,Na⁺堆积和Mg²⁺,K⁺丢失,并呈浓度依赖性。此外,钙反常时心肌组织中微量元素Fe,Zn含量下降,Cu含量增加,而Tet可抑制Fe及Zn含量的下降。维拉帕米(Ver)也有类似作用,电镜下,Tet可部分减轻钙反常时心肌组织超微结构的破坏。     

粉防已碱对大鼠心肌微粒体ATPases的作用

体外在常规反应条件下,粉防已碱(Tet)对大鼠心肌微粒体Na⁺,K⁺-ATPase活性无明显影响,但浓度依赖性抑制Mg²⁺-ATPase(IC₅₀=179μmol/L).Tet 10和100μmol/L使哇巴因(Oua)抑制Na⁺,K⁺-ATPase的量效曲线平行右移.Tet 100μmol/L可显著提高低K⁺或高Ca²⁺浓度时的Na⁺,K⁺-ATPase活性,但未能明显增加低Na⁺浓度时该酶的活性.动力学分析提示Tet 100μmol/L增加Na⁺,K⁺-ATPase对ATP的亲和力,但不改变其最大反应速度。     

前胡香豆素对肾型高血压大鼠左室肥厚及心肌胞内钙、Na+,K+-ATP酶和Ca2+,Mg2+-ATP酶活性的影响

目的研究前胡香豆素组分对肾型高血压左室肥厚的预防和逆转作用及机制。方法用两肾一夹肾型高血压左室肥厚大鼠(RHR)模型,测定前胡香豆素组分对其血压、左室湿重、心肌细胞面积、胞内静息钙及胞膜和线粒体ATP酶活性的影响。结果前胡香豆素组分(30 mg·kg^-1·d^-1,ig)预防组及逆转组大鼠血压、左室湿重/体重均较肥厚组明显降低;左室心肌细胞面积、胞内静息钙均较肥厚组降低;对KCl致钙浓度升高亦明显低于肥厚组;两组均可增加心肌细胞膜及线粒体Na⁺,K⁺-ATP酶和Ca²⁺,Mg²⁺-ATP酶活性。结论前胡香豆素组分可预防及逆转RHR左室肥厚,减少心肌细胞内钙含量,增加ATP酶活性。     

羟苯氨酮强心作用的生化机理研究

目的：研究羟苯氨酮(oxyphenamone, Oxy)强心作用的生化机理。方法：采用Na⁺,K⁺-ATP酶活性和cAMP-PDE活性、肌浆网Ca²⁺-ATP酶活性和cAMP含量以及心肌肌原纤维Ca²⁺,Mg²⁺-ATP酶活性等测定法,研究Oxy对它们的影响,并与milrinone和MCI-154作比较。 结果：Oxy对Na⁺,K⁺-ATP酶和PDE无抑制作用,也不影响心肌cAMP含量,但能显著增强心肌肌原纤维对Ca²⁺的敏感性,高浓度时轻度抑制心肌肌浆网Ca²⁺-ATP酶活性。结论：Oxy的强心作用方式不同于强心苷、β受体激动剂和PDE抑制剂等强心药,可能为一种新的钙增敏性强心药物。     

芪参胶囊对大鼠局灶性脑缺血再灌注损伤的保护作用

目的研究芪参胶囊对大鼠局灶性脑缺血再灌注损伤的保护作用。方法用线栓法建立大鼠局灶性脑缺血模型,大鼠于缺血1h再灌注2h断头取脑,检测大脑组织Ca²⁺]-ATPase,Na⁺],K⁺]-ATPase,NOS活性和NO,水的含量及大脑皮层神经元内游离钙离子浓度,行为学评价及梗死面积,常规石蜡切片,HE染色,作病理学检查。结果芪参胶囊显著降低缺血再灌注后大脑皮层神经元内游离钙离子浓度及大脑组织NOS活性,NO的含量和水肿程度及梗死面积;显著增强Ca²⁺]-ATPase,Na⁺],K⁺]-ATPase的活性;病理学检查显示芪参胶囊能明显减轻脑水肿及神经元坏死程度。结论芪参胶囊对大鼠局灶性脑缺血再灌注损伤有明显保护作用。     

Effects of crocetin on the matrix metalloproteinases in cardiac hypertrophy induced by norepinephrine in rats

The effects of crocetin on the cardiac hypertrophy induced by long-term treatment with norepinephrine (NE) in rats have been investigated. The activities of matrix metalloproteinases (MMP-2 and MMP-9) have been assayed by gelatin SDS-PAGE zymography. The expressions of MMP-2 and MMP-9 were detected by RT-PCR. ATPase activity and hydroxyproline contents were measured with a commercial kit. The results show that crocetin blocked the development of left ventricular hypertrophy induced by NE, decreased the level of collagen in myocardium, enhanced both the Na⁺-K⁺ ATPase activity in cardiac tissue and the Ca²⁺-Mg²⁺ ATPase activity in mitochondria and inhibited significantly the activity of MMP-2 and the expressions of MMP-2 and MMP-9. These results suggest that crocetin may prevent cardiac hypertrophy induced by NE in rats.     

缬沙坦与福辛普利对儿茶酚胺诱导的心肌肥厚的影响(英文)

目的:研究血管紧张素Ⅱ受体拮抗剂缬沙坦和新型血管紧张素转化酶抑制剂福辛普利对心肌肥厚的影响.方法:SD大鼠ip去甲肾上腺素1.5 mg·kg~(-1)·d~(-1)×15 d,造成心肌肥厚模型.缬沙坦ig 15 mg· kg~(-1)·d~(-1)×15 d,福辛普利ig 30 mg·kg~(-1)·d~(-1)×15 d.测量心重指数,心肌胶原含量,肌球蛋白ATP酶及细胞膜和线粒体Na~ ,K~ -ATP酶,Ca~(2 )-ATP酶的活性,并检测此模型中心肌细胞的凋亡水平.结果:缬沙坦和福辛普利均能阻止心肌肥厚的发生,减少胶原合成,提高肌球蛋白ATP酶及细胞膜和线粒体Na~ ,K~ -ATP酶、Ca~(2 )-ATP酶的活力,抑制心肌细胞的凋亡.结论:缬沙坦和福辛普利可防止儿茶酚胺诱导的心肌重塑,心肌细胞凋亡可能在儿茶酚胺诱导的心肌重塑中起重要作用.     

Effects of crocetin on antioxidant enzymatic activities in cardiac hypertrophy induced by norepinephrine in rats

Crocetin, a carotenoid isolated from the Chinese herbal medicine Crocus sativus L. (Saffron), has been shown to have cardiovascular protective effects. The present study investigated the protective action of the antioxidant crocetin against cardiac hypertrophy induced by norepinephrine (NE). This was evaluated by assaying for pathological histological changes with an optical microscope and cell image analysis system. Lipid peroxidation was quantified using thiobarbituric acid-reactive substances (TBARS). Myocardial superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and myocardial catalase (CAT) activities were assayed to evaluate the antioxidant capacity. After long term treatment with NE, antioxidant enzymatic activities were significantly decreased, while products of lipid peroxidation increased. Crocetin markedly reduced the content of lipid peroxidation (LPO), increased the GSH-Px and SOD activity in cardiac hypertrophy, and significantly improved the myocardial pathological histological changes induced by NE. These results suggest that the cardioprotective effects of crocetin are related to modulation of endogenous antioxidant enzymatic activities. Comparing crocetin with captopril, our results indicated that antioxidant activity is an important factor in the therapy of cardiac hypertrophy, but as an antioxidant only, its effects may be limited.     

Urotensin Ⅱ accelerates cardiac fibrosis and hypertrophy of rats induced by isoproterenol1

AIM: To study whether urotensin II (UII), a potent vasoconstrictive peptide, is involved in the development of cardiac hypertrophy and fibrogenesis of rats induced by isoproterenol (ISO). METHODS: Thirty male Wistar rats were randomly divided into 3 groups. Group 1 was the healthy control group, group 2 was the ISO group, and group 3 was the ISO+UII group. In groups 2 and 3, ISO (5 mg x kg(-1) x d(-1)) was given (sc) once daily for 7 d. Group 3 was also given UII in the first day [3 nmol/kg (5 microg/kg), iv], followed by sc (1.5 microg/kg) twice daily. Group 1 received 0.9% saline. UII receptor (UT) mRNA expression was determined by RT-PCR. The contents of UII and angiotensin II (Ang II) were determined by radioimmunoassay. In vitro, the effects of UII on DNA/collagen synthesis of cardiac fibroblasts were determined by [3H]thymidine/[3H]proline incorporation. RESULTS: The ratio of heart weight/body weight, plasma lactate dehydrogenase activity, myocardial malondialdehyde and hydroxyproline concentration increased significantly in the ISO group, as well as UT mRNA expression, plasma and cardiac UII and ventricular Ang II, compared with the control group (P< 0.01). ISO induced significant myocardial fibrogenesis. Moreover, UII+ISO co-treatment significantly increased the changes of biochemical markers of injury and the degree of cardiac hypertrophy and fibrosis. In vitro, 5 x 10(-9 )-5 x 10(-7 ) mol/L UII stimulated [3H]thymidine/[3H] proline incorporation into cardiac fibroblasts in a dose-dependent manner (P< 0.01). CONCLUSION: These results suggest that UII was involved in the development of cardiac fibrosis and hypertrophy by synergistic effects with ISO.     

EGCG inhibits cardiomyocyte apoptosis in pressure overload-induced cardiac hypertrophy and protects cardiomyocytes from oxidative stress in rats

AIM: To investigate the effects of epigallocatechin gallate (EGCG) on pressure overload and hydrogen peroxide (H2O2) induced cardiac myocyte apoptosis. METHODS: Cardiac hypertrophy was established in rats by abdominal aortic constriction. EGCG 25, 50 and 100 mg/kg were administered intragastrically (ig). Cultured newborn rat cardiomyocytes were preincubated with EGCG, and oxidative stress injury was induced by H2O2. RESULTS: In cardiac hypertrophy induced by AC in rats, relative to the model group, EGCG 25, 50 and 100 mg/kg ig for 6 weeks dose-dependently reduced systolic blood pressure (SBP) and heart weight indices, decreased malondialdehyde (MDA) content, and increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity, both in serum and in the myocardium. Also, treatment with EGCG 50 and 100 mg/kg markedly improved cardiac structure and inhibited fibrosis in HE and van Gieson (VG) stain, and reduced apoptotic myocytes in the hypertrophic myocardium detected by terminal transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay. In the Western blot analysis, EGCG significantly inhibited pressure overload-induced p53 increase and bcl-2 decrease. In H2O2-induced cardiomyocyte injury, when preincubated with myocytes for 6-48 h, EGCG 12.5-200 mg/L increased cell viability determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. EGCG also attenuated H2O2-induced lactate dehydrogenase (LDH) release and MDA formation. Meanwhile, EGCG 50 and 100 mg/L significantly inhibited the cardiomyocyte apoptotic rate in flow cytometry. CONCLUSION: EGCG inhibits cardiac myocyte apoptosis and oxidative stress in pressure overload induced cardiac hypertrophy. Also, EGCG prevented cardiomyocyte apoptosis from oxidative stress in vitro. The mechanism might be related to the inhibitory effects of EGCG on p53 induction and bcl-2 decrease.     

Inhibition of matrix metalloproteinases prevents cardiac hypertrophy induced by beta-adrenergic stimulation in rats

Insulin-like growth factor (IGF) -I is one of the candidates for cardiac hypertrophy induced by beta-adrenergic stimulation. However, the mechanisms by which the biologic actions of IGF-I are regulated under this condition remain unclear. IGF-I becomes bioavailable for its receptors upon its dissociation from IGF-binding protein (IGFBP) through IGFBP degradation. Because matrix metalloproteinases (MMPs) have been implicated in the degradation of IGFBPs, the authors investigated the role of MMPs in the regulation of the IGF-I action through the degradation of IGFBPs in cardiac hypertrophy induced by beta-adrenergic stimulation. They examined the expression of MMPs in cardiac tissues of rats infused with isoproterenol (3 mg/kg per day), the effect of a MMP inhibitor, SI-27 (5 mg/rat per day), on cardiac hypertrophy, and the expression of IGF-I and IGFBP-3. MMP-1 and -2 activities increased and IGFBP-3 was degraded in heart hypertrophied by isoproterenol. MMP inhibition caused a regression in the myocyte hypertrophy in association with the suppression of both IGF-I protein in myocytes and the degradation of IGFBP-3 protein. These results suggest that the induction of myocyte hypertrophy by isoproterenol is mediated, at least in part, by a modulation of the IGF-I axis.     

西红花酸对心肌成纤维细胞增殖和胶原合成的影响

目的:探讨西红花酸(crocetin)对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导的心肌成纤维细胞(cardiac fibroblasts,CFB)增殖和胶原合成的影响及其作用机制。方法:体外培养新生SD大鼠CFB,建立AngⅡ诱导新生大鼠CFB纤维化模型;MTT法检测CFB的增殖;羟脯氨酸测定检测CFB胶原含量;流式细胞分析仪测定细胞周期;实时荧光定量PCR(Q-PCR)检测Ⅰ型、Ⅲ型胶原蛋白、间质胶原酶(MMP-2)、组织金属蛋白酶抑制因子-1(TIMP-1)、转化生长因子β1(TGF-β1)的基因表达;蛋白免疫印迹(Western Blot)检测细胞P27^kip1(P27)蛋白的表达。结果:(1)在一定浓度范围里,crocetin能抑制AngⅡ引起的CFB增殖和胶原合成,并呈剂量依赖;(2)CFBG0/G1期百分率随crocetin浓度增加而增加,S期、G2/M期百分率和增殖指数随crocetin浓度增加而减少,与AngⅡ组相比差异有统计学意义(P<0.05或P<0.01);(3)Crocetin能明显降低Ⅰ型、Ⅲ型胶原、TIMP1、TGF-β1的表达,提高MMP-2的表达;(4)Crocetin能增加P27蛋白表达。结论:Crocetin通过抑制AngⅡ诱导的CFB增殖和胶原合成起到抗心肌纤维化作用,其机制可能与细胞因子分泌和对基质金属蛋白酶的调节有关。     

苄普地尔消退L－甲状腺素诱发的大鼠心肌肥厚及其质膜Ca~（2＋），Mg~（2＋

研究了苄普地尔对Ｌ－甲状腺素（１ｍｇ·ｋｇ－１·ｄ－１×７ｄ）诱发的大鼠心肌肥厚和心肌质膜Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶活力增高的影响，经苄普地尔１０或２０ｍｇ·ｋｇ－１·ｄ－１ｐｏ治疗３ｄ后，心肌肥厚及其升高的Ｃａ２＋，Ｍｇ２＿－ＡＴＰ酶活力和Ｖｍａｘ均降至正常，但甲状腺素引起的该酶对ＡＴＰ的亲和力降低未被苄普地尔改变。苄普地尔组左心室蛋白质含量较未治疗组亦显著减少，但未恢复至正常。结论：苄普地尔消退Ｌ－甲状腺素诱发的大鼠心肌肥厚，心肌Ｃａ２＋，Ｍｇ２＋－ＡＴＰ酶活力增高和蛋白质生物合成的增加。