Autonomic nervous system mediates the cardiovascular effects of Rhodiola sacra radix in rats

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola sacra (Crassulaceae) exhibits cardiovascular bioactivities and is used in Tibetan medicine for promoting circulation and preventing hypertension. However, the underlying mechanisms of its cardiovascular effects are poorly understood. AIM OF THE STUDY: The aim of this study was therefore to evaluate the cardiovascular activity of water-soluble fraction (WtF) and n-butanol-soluble fraction (BtF) of Rhodiola sacra radix and to explore its mechanism of action in propofol anesthetized Sprague-Dawley rats. MATERIALS AND METHODS: The changes of blood pressure, heart rate and cardiac contractility after systemic administration of the extracts (10-75mg/kg) were examined for at least 40min. Different antagonists were used to evaluate the mechanisms of cardiovascular effects of the extracts. RESULTS: Intravenous injection of the WtF (10, 25, 35, 50 or 75mg/kg) exhibited dose-dependent hypotension and increases in heart rate and cardiac contractility. In contrast, mild alterations in the same cardiovascular parameters were detected only at high dose (75mg/kg) BtF. The WtF-induced hypotensive, positive inotropic and chronotropic effects were significantly abolished by pretreatment with hexamethonium (30mg/kg, i.v.) or reserpine (5mg/kg, i.v.), whereas the hypotensive, but not the positive inotropic or chronotropic effect was potentiated by captopril (2.5mg/kg, i.v.). Pretreatment with methylatropine (1mg/kg, i.v.), on the other hand, reversed the positive inotropic and chronotropic but not the hypotensive effects of WtF. The WtF-induced cardiovascular responses were not affected in rats pretreated with N(G)-nitro-l-arginine methyl ester (20mg/kg, i.v.). CONCLUSIONS: We conclude that systemic administration of the WtF of Rhodiola sacra radix elicited a potent hypotensive effect that was mediated by the withdrawal of sympathetic vasomotor tone and interaction with the circulatory angiotensin system. The positive inotropic and chronotropic effects of WtF may result from a direct vagal inhibition on the heart.     

Temporal effect of Guanxin No. 2 on cardiac function, blood viscosity and angiogenesis in rats after long-term occlusion of the left anterior descending coronary artery

AIM: Cardiac infarction is one of the main causes of death in both developing and developed countries over past decades. Currently available approaches for treating patients with this disease are not satisfactory. Traditional Chinese medicines have been increasingly paid attention to. The aim of this study was to characterize the dynamic protective effects of Guanxin No. 2 decoction (GX II) on cardiac dysfunction combined with the blood viscosity and myocardial hypertrophy parameters in myocardial infarction (MI) rats. METHODS: Male Sprague-Dawley rats (180-200 g) were randomly divided into three groups: sham-operated, coronary artery ligation (CAL), and CAL plus GX II (GX II, 10.0 g raw materials/kg/d, bid, p.o.). The experiment was carried out at 4 time points as the 3rd, 7th, 14th, and 28th day after ligation. RESULT: It was found that on the one hand, GX II could significantly improve the heart function, and remarkably decrease infarct size and inhibit ventricular remodeling. On the other hand, GX II showed some unique effects such as angiogenesis which was induced in the left ventricular tissue. This result was consistent with the finding of an augmented vascular endothelial growth factor (VEGF) expression in this area. CONCLUSIONS: The studies demonstrated that GX II exerted extensively beneficial cardioprotective effect on CAL rats, it might stimulate angiogenesis of ischemic region to compensate blood supply to the heart via upregulated VEGF expression.     

老年人外周和中心动脉压的差异与冠心病的关系

目的：比较老年人外周动脉压与中心动脉压的差异,探讨二者与冠心病的关系以及可能的机制。方法：收集2010年9月至2012年1月在北京航天总医院行诊断性冠状动脉造影的386例老年的临床资料,分为冠心病组（212例）和非冠心病组（174例）。比较两组患者外周肱动脉压与中心动脉压的差异。结果：肱动脉袖带收缩压（SBP）与肱动脉内压力波测量的SBP相近,两者的升降呈平行改变,具有显著相关性（P〈0．01）。两组患者的外周动脉压与中心动脉压比较,差异有统计学意义（P〈0．05）;其中冠心病组患者的外周动脉压与中心动脉压差异更为显著。两组间各项指标比较,差异均有统计学意义（P〈0．05）。结论：外周动脉压与中心动脉压间存在差异;冠心病患者外周动脉压明显低于中心动脉压;中心动脉硬化可能与外周SBP低于中心SBP有关。     

冷牙胶侧方加压和高温热塑充填技术根尖封闭性体外实验研究

目的：比较冷牙胶侧加压充填技术与高温热塑充填技术根尖封闭效果。方法：选取离体颌牙40颗,随机分为A组（16颗牙）、B组（16颗牙）、实验阳性组（4颗牙）、实验阴性组（4颗牙）,A组采用冷牙胶侧加压充填技术,B组采用高温热塑充填技术,比较分析不同组剐渗漏现象、顺应性、封闭性能。结果：高温热塑充填技术组渗入长度[（1．01±0．16）mm]明显少于冷牙胶侧方加压充填组;1．5、3．5mm横截面封闭能力、顺应性（0．9448±0．0221、0．9543±0．0200;0．9558±0．0164、0．9722±0．0142）、1．5、3．5mm横截面100～250封闭能力（0．9496±0．0168、0．95884-0．0176）、≥250封闭能力（0．9421±0．0165、0．9516±0．0214）明显高于冷牙胶侧方充填技术（P均〈0．05）。结论：高温热塑充填技术可以增强填充材料的顺应性,减少渗漏现象,提高封闲效果。     

GuttaFlow常温流动牙胶根尖封闭性能的研究

目的:通过实验评价GuttaFlow常温流动牙胶充填系统根尖封闭性能。方法:选取72颗离体单根管恒牙,根尖区发育完整无吸收,沿釉牙骨质界截冠,15#不锈钢手用K锉通畅根管,平齐解剖根尖孔,后退l mm,记录根管预备的工作长度,使之均为15 mm。使用VDW Mtwo镍钛机用系统,采用单一长度预备技术,所有根管预备至同一标准。随机分为实验组和对照组,实验组又分A、B、C 3组,每组20颗,对照组12颗。A组用GuttaFlow常温流动牙胶充填系统充填根管,B组用连续波热牙胶充填根管,C组用Endomethasone糊剂冷牙胶侧方加压充填根管。采用葡萄糖定量法检测微渗漏,测定第1,7,14,21,28天从根管冠方向根方渗漏的葡萄糖量。结果:3组根管充填材料的根尖微渗漏值经秩和检验,A、B组微渗漏值差异无统计学意义(P>0.05),A、B组与C组微渗漏值差异具有统计学意义(P<0.05)。结论:在观察期内GuttaFlow常温流动牙胶具有较好的根尖封闭能力。     

原发性心内膜弹力纤维增生症心脏舒张功能障碍及其与收缩功能障碍的关系

目的：探讨原发性心内膜弹力纤维增生症（EFE）患儿是否存在主动舒张功能障碍及其与收缩功能障碍的关系。方法：EFE患儿44例,正常对照组50例。超声常规测量左室舒张末内径（LVEDD）、左房内径（LAD）、左室射血分数（LVEF）、左室舒张末容积（LVEDV）、E峰流速（E）、A峰流速（A）和左室等容舒张时间（IVRT）。结果：仅有舒张功能障碍7例,收缩功能障碍和舒张功能障碍并存37例。主动舒张功能障碍,即IVRT≥65ms者17例,IVRT〈65ms27例,两组比较,前者LVEF高、LAD小、E低、A高和E／A大（P〈0．05）。IVRT≥65ms时,控制变量LVEF情况下,即IVRT与LVEDD呈正相关（P〈0．05）,未发现LVEF与E／A或E相关（P〉0．05）。以IVRT70ms为分界点分成两组,IVRT≥70ms组较〈70ms组LVEDD大（P〈0．05）,而LVEF无显著差异。结论：EFE存在主动舒张功能障碍,随着舒张功能障碍加重,收缩功能下降加剧。     

血浆脑钠素与老年性左心室舒张功能不全的相关性探讨

目的探讨老年舒张性心力衰竭(DHF)患者血浆脑钠素(BNP)水平的改变及其与心功能的关系。方法应用床旁快速免疫荧光测定法(Biosite Diagnostics)检测31例DHF患者及23例健康对照者血浆BNP水平,并与心脏超声指标进行相关性分析。结果DHF患者血浆BNP水平明显高于健康对照组(617.54±235.65pg/mL vs 77.86±10.30pg/mL,P<0.01),抗心衰治疗后下降(617.54±235.65pg/mL vs 217.43±78.56pg/mL,P<0.05);BNP水平随E/A降低而增高;多因素相关分析显示BNP水平与E/A(r=-0.52,P<0.01)、LVEF(r=-0.28,P<0.05)呈负相关,与LVMI(r=0.44,P<0.01)呈正相关。结论老年DHF患者血浆BNP水平增高,DHF严重程度与BNP水平有关。     

Experimental and Theoretical Studies on Possibility of Void Filling by Magnesium in Mg-Doped Tetrahedrites

Tetrahedrites, due to their promising thermoelectric properties, are one of the materials being investigated for use in thermoelectric generators. One problem is the lack of n-type tetrahedrites, which would be beneficial for the design of tetrahedrite thermoelectric modules. Preliminary theoretical studies have shown that elements from groups I and II can be introduced into the structural voids of tetrahedrite, acting as donor dopants, and should enable n-type conductivity. Therefore, in this work, an attempt was made to obtain and study magnesium-doped tetrahedrites. A series of samples, Mg_xCu₁₂Sb₄S₁₃, with different magnesium contents were obtained and their phase and chemical compositions were characterized. It was observed that the structural changes occurring upon doping indicate that Mg atoms are likely to be embedded in the structural voids. The experimental studies have been supported by electronic structure calculations indicating that the most likely location of Mg is in the structural voids at the 6b Wyckoff position. Seebeck coefficient and resistivity measurements showed that doping with Mg reduces the concentration of holes, which is consistent with the predicted donor character of the dopant. However, the introduction of magnesium in sufficient amounts to achieve n-type conductivity was not successful.     

多普勒组织成像评价高血压左室舒张功能假性正常的价值

目的应用多普勒组织成像(DTI)技术发现血流多普勒二尖瓣口E/A“假性正常”者。方法对20例高血压左室肥厚、常规脉冲多普勒(PWD)二尖瓣口E/A>1的患者,应用DTI探测二尖瓣环运动,测量舒张早期速度(Ea)及舒张晚期速度(Aa)、计算Ea/Aa;对Ea/Aa比值组成分析后与常规PWD测量E/A相比较。结果Ea/Aa与E/A有显著差异(P<0.05),E/A出现假性正常化,而Ea/Aa<1。结论DTI评价血流多普勒E/A“假性正常”有一定的临床应用价值。     

超声检查高血压病患者左室舒张功能的变化

目的:了解高血压病患者左室舒张功能的变化.方法:随机统计高血压病各期患者60例,设正常对照组.测量舒张早期E波峰值血流速度(VE)和舒张晚期A波峰值血流速度(VA)及E/A比值.结果:正常对照组VE、VA分别为(82土13)cm/s及(51士12)cm/s,E/A＞1.高血压病1期患者VE、VA各为(80士13)cm/s及(50士11)cm/s,E/A＞1,与对照组比较无显著性差异(P＞0.05);高血压病Ⅱ期患者VE、VA各为(58±13)cm/s及(52±12)cm/s,14例E/A＞1(70%),6例＜1(30%),与正常组比较有显著性差异(P＜0.01);高血压病Ⅲ期患者,VE、VA各为(40±11)cm/s及(42士12)cm/s,3例E/A＞1(15%),17例E/A＜1(85%),与正常组比较有显著性差异(P＜0.01).结论:I期高血压患者,舒张功能改变不明显,Ⅱ期患者常有舒张功能变化,Ⅲ期患者舒张功能改变常明显.通过测量VE、VA及E/A比值对了解高血压病人舒张功能的变化有一定的临床意义.