Resiniferatoxin reduces cardiac sympathetic nerve activation to exert a cardioprotective effect during myocardial infarction

Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive.     

海沙瑞林对慢性心力衰竭大鼠心交感神经重构的影响*

目的：探讨海沙瑞林对慢性心力衰竭（ CHF）大鼠心交感神经重构的影响。 方法： SD大鼠随机分为对照 组（ Control 组）、假手术组（ Sham组）、心力衰竭组（ HF组）和海沙瑞林干预组（ HF+Hx 组），应用冠状动脉结 扎法制作CHF大鼠模型，HF+Hx 组大鼠连续4 周尾静脉注射海沙瑞林 100 μg·kg-1·d-1，其他3 组注射等量的生 理盐水。超声心动图测量左心室功能；H-E 染色及Masson 染色观察各组大鼠心肌病理结构变化；免疫组织化学和 免疫印迹检测脑钠肽（ BNP）、神经生长因子（ NGF）、酪氨酸羟化酶（TH）和生长相关蛋白43（ GAP43）表达。 结果：海沙瑞林干预升高CHF大鼠左室射血分数，改善左心室功能，减轻HF组心肌损伤结构病理改变，降低心 肌细胞内BNP 表达，增加NGF、TH和GAP43 表达，差异均具有统计学意义。 结论：CHF大鼠存在心交感神经重构， 海沙瑞林通过改变心交感神经重构， 改善心功能和CHF的预后可能是其实现心保护的机制之一。     

Sham-Controlled Randomized Trials of Catheter-Based Renal Denervation in Patients With Hypertension

Background

There are conflicting data regarding the relative effectiveness of renal sympathetic denervation (RSD) in patients with hypertension.

Stellate ganglion ischemia on the prevention of pulmonary vasospasm during bilateral carotid artery ligation: The first experimental study

Fatal pulmonary edema and hemorrhage are significant complications of endovascular treatment in steno-occlusive carotid artery disease; a rational mechanism has not been adequately examined in the literature so far. We investigated if cervical sympathetic ganglia ischemia prevents pulmonary vasospasm on the prognosis of bilateral common carotid artery ligation (BCCAL). Twenty-three adult New Zealand rabbits (4.2 ± 0.3 kg) were randomly divided into three groups: the control group (G1, n = 5), the sham group (G2, n = 6), and the BCCAL group (G3, n = 12). Common carotid arteries were dissected bilaterally in G2/G3, and permanent BCCAL was applied to only in G3. All animals were followed for 3 weeks and decapitated under general anesthesia. Histopathological changes in stellate ganglia and severity of pulmonary vasospasm-related lung edema and hemorrhage were investigated. Results were analyzed by the Kruskal–Wallis test. Two animals of G3 dead within three weeks and the remainder were sacrificed three weeks later. Subpleural petechial foci and an endotracheal bloody fluid collection were grossly observed in the lungs. Histopathologically, pulmonary artery vasospasm, perivascular and subintimal edema, interalveolar hemorrhage, and alveolar wall destructions were observed with less ischemic-degenerated neuron density-determined stellate ganglia animals. Neurodegeneration of stellate ganglia may have a beneficial effect on the prevention of lung injury during steno-occlusive carotid artery disease.     

Uterine physiology

The role of the uterus is to nurture the fetus until delivery. It is composed of the fundus, body and cervix. Functionally, the uterus is largely under hormonal control and undergoes significant change throughout pregnancy. At parturition a shift in the balance of hormones causes cervical remodelling and uterine contraction, leading to ejection of the fetus. A number of medicines impact uterine function and can be used to both induce or prevent labour.     

Alterations of sympathetic nerve fibers in avascular necrosis of femoral head

Objectives: Avascular necrosis of the femoral head (ANFH) was mainly due to alterations of bone vascularity. And noradrenaline (NA), as the neurotransmitter of the sympathetic nervous system (SNS), leads to the vasoconstriction by activating its α-Receptor. This study was to explore the nerve fiber density of the femoral head in the rabbit model of ANFH. Methods: Twenty New Zealand white rabbits were used in this study. The rabbit model of ANFH was established by the injection of methylprednisolone acetate. The nerve fiber density and distribution in the femoral head was determined using an Olympus BH2 microscope. Results: Significant fewer sympathetic nerve fibers was found in the ANFH intertrochanteric bone samples (P = 0.036) with osteonecrosis. The number of sympathetic nerve fibers was compared between the two groups. And less sympathetic nerve fibers were found in later stage ANFH samples in comparison with those of early stages. Conclusions: ANFH might be preceded by an inflammatory reaction, and an inflammatory response might lead to arthritic changes in tissue samples, which in turn reduces the number of sympathetic nerve fibers.     

晚钠电流的魅影--从交感性 T 波到Takotsubo 综合征

交感性 T 波是一类与交感应激有关的心脏电生理异常，而 Takotsubo 综合征包含了心电生理异常和心脏机械功能异常两方面。二者有共同的发病机制，包括交感兴奋、晚钠电流（late sodium current，ⅠNaL ）及钙调蛋白介导的心肌细胞电生理异常等。它们可能是同一种疾病不同的临床表现形式。     

卒中后抑郁患者交感神经皮肤反应特点及临床意义

目的探讨卒中后抑郁(PSD)患者交感神经皮肤反应(SSR)的特点及临床意义。方法共采集脑卒中患者88例,根据汉密尔顿抑郁量表(HAMD)、抑郁自评量表(SDS)评分将脑卒中患者分为无抑郁组、轻中度抑郁组、重度抑郁组,选取22名健康人群作为健康对照组。各组患者分别进行SSR测定,记录首次达峰时间及SSR波幅并进行比较分析。结果本组脑卒中患者PSD发生率为67.05%,PSD组与健康对照组相比,SSR首次达峰时间延长;波幅减低(均P0.05)。PSD组与无抑郁组相比,SSR首次达峰时间延长;SSR波幅减低(P0.05)。重度抑郁组与轻中度抑郁组相比,SSR首次达峰时间延长;SSR波幅减低(均P0.05)。结论 PSD患者SSR明显异常,抑郁越重,其异常程度越明显,SSR检测可有助于PSD诊断。