Ketanserin improves cardiac performance after myocardial infarction in spontaneously hypertensive rats partially through restoration of baroreflex function

Aim： Baroreflex dysfunction is associated with a higher rate of sudden death after myocardial infarction （MI）. Ketanserin enhances baroreflex function in rats. The present work was designed to examine whether ketanserin improves the post-MI cardiac function and to explore the possible mechanism involved. Methods： Spontaneously hypertensive rats （SHR） were treated with ketanserin （0.3 mg·k-1·d-1）. Two weeks later, blood pressure and baroreflex function were measured, followed by a ligation of the left coronary artery. The expressions of vesicular acetylcholine transporter （VAChT） and a7 nicotinic acetylcholine receptor （a7-nAChR） in ischemic myocardium, angiogenesis, cardiac function, and left ventricular （LV） remodeling were evaluated subsequently. Results： Ketanserin significantly improved baroreflex sensitivity （0.62＋0.21 vs 0.34＋0.12 ms/mmHg, P〈O.01） and vagal tonic activ- ity （heart rate changes in response to atropine, 54.8＋16.2 vs 37.6＋13.4 bpm, P〈O.01） without affecting the blood pressure or basic heart rate in SHR. Treatment of SHR with ketanserin prominently improved cardiac function and alleviated LV remodeling, as reflected by increases in the ejection fraction, fractional shortening, and LV systolic pressure as well as decreases in LV internal diameter and LV relative weight. The capillary density, vascular endothelial growth factor expression, and blood flow in the ischemic myocardium were significantly higher in the ketanserin-treated group. In addition, ketanserin markedly increased the expression of VAChT and （x7-nAChR in ischemic myocardium. Conclusion： Ketanserin improved post-MI cardiac function and angiogenesis in ischemic myocardium. The findings provide a mechanistic basis for restoring baroreflex function using ketanserin in the treatment of Ml.     

Testosterone ameliorates streptozotocin-induced memory impairment in male rats

Aim： To study the effects of testosterone on streptozotocin （STZ）-induced memory impairment in male rats.
Methods： Adult male Wistar rats were intracerebroventricularly （icv） infused with STZ （750 μg） on d 1 and d 3, and a passive avoidance task was assessed 2 weeks after the first injection of STZ. Castration surgery was performed in another group of rats, and the passive avoidance task was assessed 4 weeks after the operation. Testosterone （1 mg·kg^-1·d^-1, sc）, the androgen receptor antagonist flutamide （10 mg·kg^-1·d^-1, ip）, the estrogen receptor antagonist tamoxifen （1 mg·kg^-1·d^-1, ip） or the aromatase inhibitor letrozole （4 mg·kg^-1·d^-1, ip） were administered for 6 d after the first injection of STZ.
Results： STZ administration and castration markedly decreased both STL1 （the short memory） and STL2 （the long memory） in passive avoidance tests. Testosterone replacement almost restored the STL1 and STL2 in castrated rats, and significantly prolonged the STL1 and STL2 in STZ-treated rats. Administration of flutamide, letrozole or tamoxifen significantly impaired the memory in intact rats, and significantly attenuated the testosterone replacement in improving STZ- and castration-induced memory impairment.
Conclusion： Testosterone administration ameliorates STZ- and castration-induced memory impairment in male Wistar rats.     

Targeting at SUR2B/Kir6.1 subtype of ATP-sensitive potassium channel opener natakalim improves pressure overload-induced heart failure

Objective To explore the new stratigies targeting at SUR2B/Kir6.1 subtype against pressure overload-induced heart failure.Methods Pressure overload-induced heart failure was induced in Wistar rat by abdominal aortic banding(AAB).The effects of natakalim(1,3,9 mg·kg-1·d-1,10 weeks)were assessed on myocardial hypertrophy and heart failure,cardiac histology,vasoactive compounds,and gene expression.Isolated working heart and isolated tail artery helical strips were used to examine the influence of natakalim on heart and resistant vessels.Results Ten weeks after the onset of pressure overload,natakalim therapy potently inhibited cardiac hypertrophy and prevented heart failure.Natakalim inhibited the changes of left ventricular haemodynamic parameters,reversed the increase of heart mass index,left ventricular weight index and lung weight index remarkably.Histological examination demonstrated that there were no significant hypertrophy and fibrosis in hearts of pressure overload rat treated with natakalim.Ultrastructural examination of heart revealed well-organized myofibrils with mitochondria grouped along the periphery of longitudinally oriented fibers in natakalim group rats.The content of serum NO and plasma PGI2 was increased,while that of plasma ET-1 and cardiac tissue hydroxyproline,ANP and BNP mRNA was down-regulated in natakalim-treated rats.Natakalim at concentrations ranging from 0.01-100 μM had no effects on isolated working heart derived from Wistar rats;however,natakalim had endothelium-dependent vasodilation effects on the isolated tail artery helical strips precontracted with NE.Conclusions These results indicate that natakalim improves heart failure due to pressure overload by activating KATP channel SUR2B/Kir6.1 subtype and reversing endothelial dysfunction.     

Protective effects of betaglucin on myocardial tissue during myocardial infarction in rats and dogs

Aim： To test the protective effects of betaglucin, a novel beta-glucan, on models of myocardial infarction （MI） in rats and dogs. Methods： The left anterior descending （LAD） coronary artery occlusion model was used to induce an MI in rats and dogs. Three doses of betaglucin （10, 30 and 100 mg/kg）, propranolol （positive control, 1 mg/kg） and vehicle alone （5% glucose solution） were administered before LAD occlusion, and characteristics of the resulting MI were subsequently assessed. In anesthetized dogs, blood pressure heart rate, ventricular function, coronary artery blood flow and myocardial oxygen consumption were determined before and after the drug administration. Results： The MI mass in both rats and dogs was significantly reduced by betaglucin （30 and 100 mg/kg, P〈O.01） and propranolol （P〈O.01）. In anesthetized dogs, coronary artery blood flow was increased significantly by betaglucin （30 and 100 mg/kg, P〈O.01）, but blood pressure, heart rate and ventricular function were not changed （P〉O.05）. High-dose betaglucin （100 mg/kg） increased myocardial oxygen consumption, but not to a statistically significant level （P〉O.05）. The hemodynamic indexes were significantly changed by propranolol. Conclusion： Betaglucin has protective effects on myocardial tissue during MI in rats and dogs and has no influence on hemodynamic parameters at a therapeutic dose. The increase in coronary artery blood flow induced by betaglucin might be beneficial in the treatment of patients with MI.     

Puerarin inhibits angiotensin II-induced cardiac hypertrophy via the redox-sensitive ERK1/2, p38 and NF-κB pathways

Aim： To investigate the effects of puerarin （Pue）, an isoflavone derived from Kudzu roots, on angiotensin II （Ang II）-induced hypertrophy of cardiomyocytes in vivo and in vitro.
Methods： C57BL/6J mice were infused with Ang II and treated with Pue （100 mg·kg-1·d-1, po） for 15 d. After the treatment, systolic blood pressure （SBP） and left ventricular wall thickness were assessed. The ratios of heart weight to body weight （HW/BW） and left ventricular weight to body weight （LVW/BW） were determined, and heart morphometry was assessed. Expression of fetal-type genes （ANP, BNP and β-MHC） in left ventricles was measured using semi-quantitative RT-PCR. Mouse primary cardiomyocytes were treated with Pue （50, 100, 200 μmol/L）, then exposed to Ang II （1 μmol/L）. ROS level was examined with flow cytometry, the binding activity of NF-κB was determined using EMSA. Western blot was used to measure the levels of ERK1/2, p38 and NF-κB pathway proteins. [3H]leucine incorporation was used to measure the rate of protein synthesis.
Results： Oral administration of Pue significantly suppressed Ang II-induced increases in the myocyte surface area, HW/BW, LVW/BW, SBP and left ventricular wall thickness. Furthermore, Pue significantly suppressed Ang II-induced increases in ANP, BNP and β-MHC expression in the left ventricles in vivo. Treatment of cardiomyocytes with Pue （50–500 μmol/L） did not affect the viability of cardiomyocytes in vitro. Pretreatment of cardiomyocytes with Pue dose-dependently inhibited Ang II-induced increases in ROS production, NF-κB binding activity, protein synthesis and cell breadth. Furthermore, pretreatment with Pue significantly suppressed Ang II-induced activation of ERK1/2, p38 and the NF-κB pathway proteins and the expression of ANP and β-MHC in cardiomyocytes. The positive drug valsartan exerted similar effects on Ang II-induced cardiac hypertrophy in vivo and in vitro.
Conclusion： Pue attenuates Ang II-induced cardiac hypertrophy by inhibiting activation of the redox-sensitive ERK1/2, p38 and the NF-κB pathways.     

中西药相互作用研究:茵陈蒿与对乙酰氨基酚

The purpose of this study is to evaluate the interaction effects of In-Chen-How （Artemisia capillaries Thunb. ） on the pharmacokinetics of acetaminophen and on liver microsomal cytochrome P450 enzyme activity in rats. The rats were divided into control group （ n = 8 ） without In-Chen-How and the pretreated group （ n = 8 ） administered with In-Chen-How （ approximately 1.0 mL · kg^-1, according to weight） for 5 consecutive days. Rats in the control group received water simultaneously. Each rat was then given acetaminophen. The pharmacokinetic parameters of acetaminophen of the two groups were significantly different. In the In-Chen-How pretreated group, the maximum concentration of acetaminophen and the area under the plasma concentration-time curve were reduced about 58.4% , 56.7% and 55.4%. To further explain the results, liver microsomal suspensions were obtained from rats that were randomly divided into control and In-Chen-How pretreated group. The levels of CYP1A2 and CYP2E1 in hepatic microsomal protein from pretreated group were increased as compared to that from the control group. It indicated that In-Chen-How can stimulate the activity of CYP isozymes. The changes in the pharmacokinetics of acetaminophen resulting from the administration of In-Chen-How are related to an increase in metabolic activity of CYP1A2 and CYP2E1.     

Studies on the anti -obesity effects of betaphrine in obese animal induced by monosodium -1- glutamate

Aim： To investigate the effect of anti - obesity of Betaphring as a new anti - obesity drug in obese animal models. Methods： Obese rats was induced by SC MSG. Neonatal rats were given MSG 3mg. g^-1 continuously for 5 days from the first birthday. On the 21th day, the MSG rats were divided into six groups and administrated orally Betaphrine10, 30, 90mg. kg^-1. d^-1 or Sibutramine 4 mg. kg^-1. d ^-1 or 0. 9% NS for 28 days respectively. At the end of the experiments, the animal samples were examined. RESULTS： Betaphrine30, 90mg. kg^-1. d^-1 ig for 4wk could decrease body weight, the areas of adipose cell, the total weight of white adipose tissue and brown adipose tissue, and increase the level of serum HDLc and the number of adipose cell in the sample obese rats. But no effect was shown on the level of serum glucose, triglyceride, ins, npy, leptin , Lee＇s index, and the level of ins, npy, leptin in hypothalamus homogenate. CONCLUSION： Betaphrine is an effective agent of anti - obesity effect in MSG obese rats.     

Protective effect of raloxifene on lipopolysaccharide and acid- induced acute lung injury in rats

Aim： To evaluate the protective effect of oral raloxifene on acute lung injury. Methods： Thirty adult, male Sprague-Dawley rats each weighing 180-210 g were used and divided into 3 groups： the raloxifene-lipopolysaccharide （LPS）-HCI group （n=10）, the LPS-raloxifene-HCl group （n=10）, and the placebo group （n=10）. All the rats were injected intraperitoneally （ip） with 5 mg/kg LPS, and raloxifene （30 mg/kg） was orally administered 1 h before and 14 h after LPS injection into the raloxifene-LPS-HCl and the LPS-raloxifene-HCl groups, respectively; the placebo group received nothing. Sixteen hours after LPS injection, all the animals were anesthetized and the femoral artery was cannulated. All the rats received a direct intratracheal （IT） injection ofHCl （pH 1.2; 0.5 mL/kg）. The mean arterial pressure （MAP） and blood gas concentrations were measured. Fifteen rats （5 in each group, respectively） underwent a micro positron emission tomography （microPET） scan of the thorax 4 h after HCI instillation. The wet/dry （W/D） weight ratio determination and histopathological examination were also performed. Results： The rats in the LPS-raloxifene-HCl group had a lower [^18F]fluorodeoxyglucose uptake compared with the rats in the placebo group （4.67±1.33 vs 9.01±1.58, respectively, P〈0.01）. The rats in the LPS-raloxifene-HCl group also had a lower histological lung injury score （8.20± 1.23 vs 12.6±0.97, respectively, P〈0.01） and W/D weight ratio （5.335±0.198 vs 5.886±0.257, respectively, P〈0.01） compared to the placebo group. The rats in this group also showed better pulmonary gas exchange and more stable mean arterial pressure （MAP） compared to the placebo group. Conclusion： Raloxifene provides a significant protective effect on acute lung injury in rats induced first by LPS ip injection and then by HCI IT instillation.     

The peroxisome proliferator-activated receptor-α （PPAR-α） agonist,AVE8134, attenuates the progression of heart failure and increases survival in rats

Aim： To investigate the efficacy of the peroxisome proliferator-activated receptor-α （PPARa） agonist, AVE8134, in cellular and experimental models of cardiac dysfunction and heart failure.
Methods： In Sprague Dawley rats with permanent ligation of the left coronary artery （post-MI）, AVE8134 was compared to the PPARy agonist rosiglitazone and in a second study to the ACE inhibitor ramipril. In DOCA-salt sensitive rats, efficacy of AVE8134 on cardiac hypertrophy and fibrosis was investigated. Finally, AVE8134 was administered to old spontaneously hypertensive rats （SHR） at a nonblood pressure lowering dose with survival as endpoint. In cellular models, we studied AVE8134 on hypertrophy in rat cardiomyocytes nitric oxide signaling in human endothelial cells （HUVEC） and LDL-uptake in human MonoMac-6 cells.
Results： In post-MI rats, AVE8134 dose-dependently improved cardiac output, myocardial contractility and relaxation and reduced lung and left ventricular weight and fibrosis. In contrast, rosiglitazone exacerbated cardiac dysfunction. Treatment at AVE8134 decreased plasma proBNP and arginine and increased plasma citrulline and urinary NOx/creatinine ratio. In DOCA rats, AVE8134 prevented development of high blood pressure, myocardial hypertrophy and cardiac fibrosis, and ameliorated endothelial dysfunction. Compound treatment increased cardiac protein expression and phosphorylation of eNOS. In old SHR, treatment with a low dose of AVE8134 improved cardiac and vascular function and increased life expectancy without lowering blood pressure. AVE8134 reduced phenylephrine-induced hypertrophy in adult rat cardiomyocytes. In HUVEC, Ser-1177-eNOS phosphorylation but not eNOS expression was increased. In monocytes, AVE8134 increased the expression of CD36 and the macrophage scavenger receptor 1, resulting in enhanced uptake of oxidized LDL.
Conclusion： The PPARa agonist AVE8134 prevents post-MI myocardial hypertrophy, fibrosis and cardiac dysfunction. AVE8134 has beneficial effects against hy     

Osteogenic effects of D（＋）β-3,4-dihydroxyphenyl lactic acid （salvianic acid A,SAA） on osteoblasts and bone marrow stromal cells of intact and prednisone-treated rats

Aim： Previous studies have shown that D（＋）β-3,4-dihydroxyphenyl lactic acid （salvianic acid A, SAA） has anabolic effects on prednisone （GC）-induced osteoporosis in rats. The current study aims to investigate the molecular mechanism of SAA＇s impact on osteogenesis and adipogenesis in bone marrow stromal cells in intact and GC-treated rats.
Methods： For in vitro study, newborn rat calvaria osteoblasts （rOBs） and rat bone marrow stromal cells （rMSCs） were isolated, identified and cultured with SAA at different concentrations to evaluate SAA＇s influence on osteogenesis and adipogenesis. In addition, 3-month-old Sprague-Dawley （SD） male rats were treated with distilled water, prednisone alone （3.0 mg·kg^-1·d^-1） or prednisone （3.0 mg·kg^-1·d^-1） and SAA （25 mg·kg^-1·d^-1） for 45 d. At the end point, the different groups of rMSCs were isolated by density-gradient centrifugation and cultured.
Results： （1） At 0.1-10.0 mg/L, SAA increased ALP activity, type I collagen （Coil-I） mRNA and OPG mRNA expression and stimulated nodule mineralization of rOBs. SAA （0.5 mg/L） also significantly increased the ALP activity of rMSCs without a need for osteogenesis-inducing medium. At 5.0 mg/L, SAA decreased the number of adipocytes with less lipid droplet formation from the rMSCs, which typically undergo adipocyte induction. （2） Coll-I expression was markedly decreased, whereas lipoprotein lipase （LPL） mRNA expression increased by 98% when compared with the first generation of rMSCs in GC-treated rats. The SAA-treated rats demonstrated an over 2-fold increase in Coll-I expression when compared with intact rats and further showed a significant decrease in LPL expression when compared with GC-treated rats. When rMSCs were co-cultured with SAA （0.5 mg/L） in vitro, SAA did not affect Coll-I and LPL gene expression in intact rats but significantly increased ColM and decreased LPL gene expression in GC-treated rats.
Conclusion： SAA protected bone from GC-i     

卡托普利和低剂量阿司匹林相互作用对心衰大鼠左室重建的影响

目的：观察联用卡托普利和低剂量阿司匹林对心衰大鼠左室重建的影响。方法：采用冠状动脉结扎致急性心肌梗死和心梗后慢性心力衰竭大鼠模型，按照正交设计试验方案服药5周，测定左室重量／体重比（LVW／BW），心肌组织胶原VG染色，图像分析系统测量心肌胶原容积分数（ICVF），血管周围胶原面积（PVCA）。结果：与正常组，假手术组相比，急性心梗模型组，慢性心衰模型组LVW／BW，ICVF，PVCA均显著升高（P＜0．01），卡托普利显著逆转左室肥厚（P＜0．05），减轻间质纤维化（P＜0．05），阿司匹林对其无影响（P＞0．05），但二者联用存在显著的相互作用（P＜0．01，P＜0．05），且表现为拮抗效应。卡托普利对血管周围纤维化无显著性作用（P＞0．05），但与阿司匹林存在显著的相互作用（P＜0．05），其拮抗低剂量阿司匹林对血管周围纤维化的显著不利作用（P＜0．05），结论：低剂量阿司匹林减弱卡托普利逆转左室肥厚及减轻间质纤维化的作用，其本身对血管周围纤维化的发生也存在不利影响。     

低聚葡萄籽原花青素对异丙肾上腺素诱导大鼠心室重构的影响

研究低聚葡萄籽原花青素(oligomeric grape seed proanthoc yanidins,GSP)对异丙肾上腺素(isoproterenol,ISO)致大鼠心室重构的保护作用并初步探讨其机制。采用皮下注射ISO致大鼠心室重构模型,以GSP(50,100及150mg·kg-1)灌胃给药,PowerLab监测大鼠心功能,计算大鼠全心重量指数(HW/BW)和左心重量指数(LVW/BW),观察心肌病理学改变,测定左心室心肌组织中羟脯氨酸(Hyp)含量、血清中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。结果表明,与空白对照组相比,ISO组大鼠心功能明显受损,心脏重量指数HW/BW和LVW/BW、心肌细胞横截面积(CSA)、心肌间质胶原容积分数(CVF)和心肌血管周围胶原面积(PVCA)、心肌组织Hyp含量明显升高,血清SOD活性下降,MDA含量升高。与ISO组相比,GSP能明显改善心功能,降低心脏HW/BW和LVW/BW、CSA、CVF、PVCA和左心室心肌组织中Hyp含量,增加血清SOD活性,降低血清MDA含量。GSP对ISO诱导的大鼠心室重构具有明显的逆转作用,其机制可能与抗氧化应激,提高机...     

5-HT_(2B)受体阻断剂在去甲肾上腺素诱导大鼠心肌肥厚中的作用

目的观察应用5-HT2B受体阻断剂对去甲肾上腺素(NE)诱导的心肌肥厚的影响,并初步分析5-HT2B受体在NE诱导心肌肥厚中的作用及机制。方法雄性SD大鼠46只随机分为试验组(n=32)及对照组(n=14),试验组采用腹腔注射NE(1.5 mg/kg,2次/d,28 d)的方法建立心肌肥厚模型,自第15天起按分组分别注射SB204741(5-HT2B受体阻断剂;0.5 mg/kg,n=8;2 mg/kg,n=8)或SDZ SER 082(另一种5-HT2B受体阻断剂;1 mg/kg,n=8)14 d,对照组分别注射生理盐水(n=8)或SB204741(2 mg/kg,n=8)。检测心肌肥厚指数包括左心室重量与体重之比(LVW/BW)和左心室游离壁厚度与体重之比(LVWT/BW),以及心肌组织中5-HT含量。结果 NE诱导心肌肥厚过程中注射SB204741可显著减轻心肌肥厚的程度,并剂量依赖地降低肥厚心肌组织中5-HT含量;而单独给予SB204741处理对心肌肥厚指数和心肌组织中5-HT含量没有影响。SDZ SER 082可产生与SB204741相同的作用效果。结论 5-HT2B受体参与NE诱导的心肌肥厚的进展。     

Ameliorative effect of combination of fenofibrate and rosiglitazone in pressure overload-induced cardiac hypertrophy in rats

The present study has been designed to investigate the effects of fenofibrate, a peroxisome proliferator-activated receptor (PPAR)alpha agonist, rosiglitazone, a PPARgamma agonist and the combination of both fenofibrate and rosiglitazone in partial abdominal aortic constriction (PAAC)-induced pathological cardiac hypertrophy in rats. Rats were subjected to PAAC for 4 weeks to produce pathological cardiac hypertrophy. The fenofibrate (3 mg/kg day(-1), p.o.), rosiglitazone (3 mg/kg day(-1), p.o.) and the combination of both fenofibrate (3 mg/kg day(-1), p.o.) and rosiglitazone (3 mg/kg day(-1), p.o.) were administered 3 days before PAAC and continued for 4 weeks after PAAC. The development of cardiac hypertrophy was assessed in terms of measuring ratio of left ventricular (LV) weight to body weight (LVW/BW), LV wall thickness (LVWT), LV protein content and LV collagen content. Further, the collagen accumulation in left ventricle was analyzed using picrosirius red staining. Moreover, the cross-sectional area (CSA) of cardiomyocytes was assessed using hematoxylin and eosin staining and measured using a NIH Scion image analyzer. The PAAC produced cardiac hypertrophy by increasing LVW/BW, LVWT, LV protein content, LV collagen content and mean CSA of cardiomyocytes. However, treatment with fenofibrate and rosiglitazone either alone or in combination significantly attenuated PAAC-induced increase in LVW/BW, LVWT, LV protein content, LV collagen content and mean CSA of cardiomyocytes. The combination of fenofibrate and rosiglitazone was more effective in attenuating the PAAC-induced cardiac hypertrophy than either drug alone. Thus, it may be concluded that dual activation of PPARalpha and PPARgamma may provide synergistic benefits in preventing the development of pathological cardiac hypertrophy.     

辛伐他汀抑制心肌细胞Rho A、Rho GTPase表达对心室肥厚的影响

目的 探讨辛伐他汀对心力衰竭模型兔抑制心肌肥厚、改善心功能的影响及机制.方法 24只新西兰白兔,均分四组.除假手术组外,通过破坏主动脉瓣和缩窄腹主动脉,增加左心室前、后负荷,建立慢性心力衰竭模型;术后(除心衰对照组)早干预组(即起,连续8周)和晚干预组(第5周起,连续4周)予辛伐他汀每天5 mg/kg灌胃,实验结束取心肌细胞,Westem-blot检测细胞膜Rho A蛋白表达,[γ~-~(32)P]电泳分析Rho GTPase活性;实验前、结束时均行超声心动图检查.结果 心衰对照组室间隔厚度(LVSd)、左心室舒张期内径(LVIDd)、左心室后壁厚度(LVPwd)、左心室收缩期内径(LVIDs)、心脏重量(Hw)、左心室重量(LVW)、心脏/体重(HW/BW radio)、左心室/体重(LVW/BW radio)明显高于假手术和早、晚干预组(P<0.05,P<0.01);左室射血分数(EF)、左室长轴缩短率(FS)明显低于假手术组和早、晚干预组(P<0.05,P<0.01);心肌细胞膜Rho A蛋白表达、Rho GTPase活性明显高于假手术组和早、晚干预组(P<0.01).结论 辛伐他汀可抑制细胞膜RhoA蛋白表达、Rho GTPase活性,从而抑制心肌肥厚、改善心功能.     

贝那普利与螺内酯合用对大鼠肾血管性高血压的治疗作用

采用大鼠两肾一夹高血压模型,观察贝那普利(Ben)和螺内酯(Spi)合用对高血压大鼠的收缩压(SBP),左心室肥厚及左心室心肌纤维化的作用. 夹肾动脉术后15周,与假手术组比,模型组SBP,左心室重(LVW)/体重(BW)和左心室胶原蛋白浓度分别增加95％,56％和78％. 与模型对 照组比较,Ben 15 mg·kg^-1·d^-1 ig,治疗9周,SBP,LVW/BW及左心室胶原含量分别下降了30％,25％和12％;Ben 15 mg·kg^-1·d^-1 ig与Spi 7.5 mg·kg^-1·d^-1 ig 合用9周,SBP,LVW/BW 和左心室胶原浓度分别降低了42％,34％和37％,均显著低于Ben组. 本研究提示,Ben和Spi合用在抑制高血压大鼠左心室肥厚和心肌纤维化方面的作用有加强.     

依那普利与牛磺酸对肾性高血压大鼠血压、左室肥厚及血小板聚集率的影响

二肾一夹型高血压大鼠的血压,血小板聚集率及左心室与体重之比均高于正常对照组成。依那普利(enalapril)6mg·kg^-1·d^-1,牛磺酸(taurine)30mg·k^-1·d^-1均可降低肾性高血压大鼠的血压(降压幅度分别为39.2%和36.60%),抑制血小板聚集率和逆转左室肥厚,但与正常对照组仍有差异。两药合用后,其降压和抑制血小板聚集作用明显增强,与正常组无显著差异,逆转左室肥厚作用虽亦比单独用药作用明显,但左室重/体重仍高于正常组。     

辛伐他汀对慢性心力衰竭兔心肌PPARγ mRNA、蛋白表达及核因子κB表达、活性的影响

目的观察辛伐他汀对兔慢性心力衰竭模型心肌肥厚、心功能的影响,探讨辛伐他汀抑制心肌肥厚、改善心功能的机制。方法24只新西兰白兔分为4组,1组为假手术组。2、3、4组给予主动脉瓣返流及腹主动脉缩窄术,其中2组为心衰对照组;3组:早干预组,术后给予辛伐他汀5mg·kg-1·d-1灌胃连续8wk;4组:晚干预组,术后4wk给予辛伐他汀5mg·kg-1·d-1灌胃连续4wk。观察开始及结束时左室舒张末压(LVEDP)。实验结束时,观察左心室重量(LVW)、心脏重量(HW),计算左心室重量指数(LVW/BW)、心脏重量指数(HW/BW)。RT-PCR分析各组PPARγmRNA表达。Western blot分析心肌细胞核PPARγ和p65蛋白表达,电泳迁移率变动试验分析p65活性。结果早、晚干预组LVW、HW、HW/BW均低于心衰对照组(P<0.05,P<0.01),早干预组(LVW/BW)低于心衰对照组(P<0.01)。早、晚干预组左室舒张末压低于心力衰竭组(P<0.01)。心衰对照组心肌组织PPARγ蛋白和mRNA表达低于假手术组(P<0.01),p65蛋白表达及活性高于假手术组(P<0.01)。辛伐他汀干预后,早干预组、晚干预组PPARγ蛋白和mRNA表达增加(P<0.01),p65蛋白表达及活性降低(P<0.01)。结论辛伐他汀抑制心肌肥厚、改善心功能,其机制与增加PPARγ表达、降低p65蛋白表达及活性有关。     

环维黄杨星D对异丙肾上腺素致小鼠心肌肥厚保护作用的初步研究

目的：初步研究环维黄杨星D（Cvb—D）对小鼠心肌肥厚的保护作用。方法：皮下注射异丙肾上腺素（Iso）1mg·kg^-1,bid,连续14d,制备小鼠心肌肥厚模型,各治疗组分别给予环维黄杨星D（6,9,12mg·kg^-1）和阳性对照卡托普利（100mg·kg^-1）灌胃给药,末次给药24h后处死小鼠,测量小鼠心脏质量指数（全心质量／体质量）和左心室质量指数（左心室质量／体质量）,并观察心肌组织病理形态学改变,以评价Cvb—D对小鼠心肌肥厚的保护作用。结果：与空白对照组比较,Iso模型组小鼠心脏重量指数明显升高,病理切片可见心肌肥厚改变。与Iso组相比,Cvb—D高剂量组能明显降低小鼠心脏质量指数和左心室质量指数（P〈0．05或0．01）,病理切片可见损害较模型组减轻。结论：环维黄杨星D对Iso诱导的小鼠心肌肥厚具有一定的保护作用,其机制有待进一步研究阐明。     

高血压性左心室肥厚与心肌原癌基因c-fos表达

采用自发性高血压大鼠(SHR)和两肾一夹型(2K1C)肾血管性高血压大鼠模型，研究细胞核内原癌基因c-fos在高血压性左心室肥厚(LVH)发生，发展过程中的作用. 结果表明：SHR在8-10周龄时已有明显的高血压和LVH，其收缩压(SBP)与左室重/体重比(LVW/BW)均显著高于同龄的WKY大鼠. 20-22周龄与40-42周龄时，SHR的SBP，LVW/BW及左心室c-fos基因表达水平均明显高于同龄对照组WKY大鼠. 2K1C大鼠左肾动脉缩窄1周后发生明显的LVH，同时伴左心室c fos基因的高表达，至术后3和10周仍保持较高水平. 钙拮抗剂尼群地平(10 mg·kg^-1 ig，每日2次，连续10周)或血管紧张素AT₁受体阻断剂洛沙坦(30 mg·kg^-1·d^-1 ig，连续10周)治疗均可逆转2K1C大鼠SBP的增高和LVH的发生与发展，同时左心室c-fos基因表达水平降低. 结果提示心肌原癌基因c-fos的高表达参与高血压性LVH的发生，发展过程.