去肾交感神经术对自发性高血压大鼠肾胺酶及酪氨酸羟化酶的影响

目的:通过观察自发性高血压大鼠（SHR）去肾交感神经手术前后血压、肾胺酶浓度、肾脏酪氨酸羟化酶（TH）与肾胺酶表达水平的变化,探讨去肾交感神经术降低血压的可能机制。方法:将SHR 大鼠（n=48）随机分为基线组、手术组、假手术组和对照组,同批同周龄WKY 大鼠（n=12）作为基线对照组,同条件喂养至12 周龄测各组血压,首批处死SHR 基线组、WKY 组,采血、取肾脏组织送检;手术组、假手术组与对照组继续监测血压,于去肾交感神经术后1,6 周时分批处死每组大鼠各6 只,分别采血、取肾脏组织送检。采用ELISA 方法测定血浆肾胺酶浓度,Western 印迹测定肾脏TH、肾胺酶蛋白表达水平。结果:与WKY 组大鼠比较,SHR 基线组大鼠血压、肾脏TH 蛋白表达水平明显升高（P<0.05),血浆肾胺酶浓度及蛋白表达水平明显下降(P<0.05);术后1 周,手术组大鼠平均动脉压与TH 蛋白表达水平较基线组明显降低且明显低于假手术组及对照组(P<0.05),手术组肾胺酶水平较基线组明显增高并明显高于假手术组及对照组(P<0.05);术后6 周,手术组平均动脉压与TH 水平较术后1 周上升而肾胺酶浓度及水平较术后1 周降低,较基线组、假手术组与对照组差异无统计学意义(P>0.05);假手术组与对照组较基线组各项指标差异无统计学意义(P>0.05)。结论:去肾交感神经术降低血压的作用可能与其抑制交感神经,升高肾胺酶浓度及其蛋白表达水平有关。     

High Salt Diet Impacts the Risk of Sarcopenia Associated with Reduction of Skeletal Muscle Performance in the Japanese Population

The World Health Organization has recommended 5 g/day as dietary reference intakes for salt. In Japan, the averages for men and women were 11.0 g/day and 9.3 g/day, respectively. Recently, it was reported that amounts of sodium accumulation in skeletal muscles of older people were significantly higher than those in younger people. The purpose of this study was to investigate whether the risk of sarcopenia with decreased muscle mass and strength was related to the amount of salt intake. In addition, we investigated its involvement with renalase. Four groups based on age and salt intake (“younger low-salt,” “younger high-salt,” “older low-salt,” and “older high-salt”) were compared. Stratifying by age category, body fat percentage significantly increased in high-salt groups in both younger and older people. Handgrip strength/body weight and chair rise tests of the older high-salt group showed significant reduction compared to the older low-salt group. However, there was no significant difference in renalase concentrations in plasma. The results suggest that high-salt intake may lead to fat accumulation and muscle weakness associated with sarcopenia. Therefore, efforts to reduce salt intake may prevent sarcopenia.     

Increased serum renalase in hemodialysis patients: is it related to left ventricular hypertrophy?

Introduction: Left ventricular hypertrophy (LVH) is one of the most common cardiac abnormalities in patients with end stage renal disease (ESRD). Hypertension, diabetes, increased body mass index, gender, age, anemia, and hyperparathyroidism have been described as risk factors for LVH in patients on dialysis. However, there may be other risk factors which have not been described yet. Recent studies show that renalase is associated with cardiovascular events. The aim of this study was to reveal the relation between renalase, LVH in patients under hemodialysis (HD) treatment.

Methods: The study included 50?HD patients and 35 healthy controls. Serum renalase levels and left ventricle mass index (LVMI) were measured in all participants and the relation between these variables was examined.

Findings: LVMI was positively correlated with dialysis vintage and C-reactive protein (CRP) (r?=?0.387, p?=?0.005 and r?=?0.597, p?r?=??0.324, p?=?0.022 and r?=??0.499, p?renalase with LVMI in the HD patients (r?=?0.263, p?=?0.065). Serum renalase levels were significantly higher in HD patients (212?±?127?ng/mL) compared to controls (116?±?67?ng/mL) (p?r?=?0.677, p?r?=?0.625, p?Discussion: In our study, LVMI was correlated with dialysis vintage, residual diuresis, CRP, and hemoglobin. LVMI tends to correlate with renalase and this correlation may be significant in studies with more patient numbers. The main parameters affecting renalase levels are dialysis vintage and serum creatinine.     

Disaster Preparedness for Renal Facilities and Patients

Background: hRenalase may degrade catecholamines and regulate sympathetic tone and blood pressure (BP). The aim of the study was to assess dopamine (DA), norepinephrine (NE), and renalase in 75 hemodialysis (HD) and 26 peritoneal dialysis (PD) patients and their correlations with heart rate (HR), BP, a type of hypotensive therapy, and residual renal function. Methods: Renalase, DA, NE were studied using commercially available assays. Results: Renalase and NE were higher and DA was lower in dialyzed groups comparing to healthy volunteers. Hemodialysis patients had lower NE and higher renalase level. Norepinephrine was higher in anuric patients in HD group. Renalase correlated with dialysis vintage and inversely with residual diuresis. Dopamine correlated with residual diuresis in the whole study cohort, with HR in PD patients, with renalase in HD patients. Norepinephrine correlated with aortic diameter in PD patients. Norepinephrine was significantly higher in patients with coronary artery disease (CAD) in HD group. Hemodialysis population with CAD had lower NE and higher DA and renalase level than their PD counterparts. In the follow up, 27% of HD group died. Cardiac death was diagnosed in 17% and there was higher renalase level than in noncardiac death. Conclusions: Elevated level of circulating renalase in dialysis patients is rather related to kidney function and the sympathetic nervous system hyperactivity found in this population. The real excess of renalase in the pathogenesis of cardiovascular disorders in patients with chronic kidney disease still remains to be proven. If confirmed, it may give a new way for pathophysiological therapy.     

肾胺酶及其在急性肾损伤中作用的研究进展

肾胺酶作为近年来新发现的一种黄素蛋白,主要由肾小管近端上皮细胞合成和分泌,在心、肝、骨骼肌等多器官系统均有表达。肾胺酶曾被认为是一种儿茶酚胺类的降解酶,并在心血管疾病的病理生理过程中起到重要作用;而近期研究对肾胺酶的结构、生物学特性及作用有了新的认识,并认为其在急性肾损伤的发生发展中起到了重要作用。本文对主要对肾胺酶的结构、功能及作用等方面进行了综述。     

Rescue of human corneal epithelial cells after alkaline insult using renalase derived peptide, RP-220

AIM: To study the effect of renalase peptide, RP-220, on cell viability of human corneal epithelial cells after alkali insult. METHODS: A dose-response relationship between cell viability and exposure to NaOH solution were characterized using cultured human corneal epithelial cells. Viability of corneal epithelial cells was determined using commercially available MTT and CyQUANT® assays. RESULTS: At a concentration of 6 mmol/L, insult with NaOH leads to reduced corneal epithelial cell viability by approximately 30%. This reduced viability was prevented by treating the cells after initial insult with the 20-amino acid renalase derived peptide (RP-220). CONCLUSION: RP-220 has a pro-survival role for RP-220 following alkaline insult to corneal epithelial cells.     

肾胺酶与心血管疾病研究进展

肾胺酶(renalase)是近年发现的一种由肾脏分泌的胺氧化酶,它可以通过降解儿茶酚胺来调节心功能与血压。肾脏分泌的激素与心血管疾病密切相关,肾胺酶作为反映心肾关系的新标志,具有降压、保护缺血心肌、改善心功能、降解儿茶酚胺等重要作用。     

肾酶与心血管疾病

肾酶是一种主要由肾脏分泌的新型黄素腺嘌呤二核苷酸依赖的胺氧化酶，能降解循环中的儿茶酚胺，调节心功能和血压。慢性肾脏疾病和终末期肾病患者血浆肾酶显著降低，其心血管疾病并发症明显增加；肾酶基因多态性与原发性高血压发病易感性增加相关；外源性肾酶能够显著降低大鼠的心肌梗死面积、心率、外周血管阻力和平均动脉压，调节心肌收缩性，改善左心室功能，提示肾酶与心血管疾病密切相关，可能具有良好的生理、病理和药理学应用前景。     

地龙降压胶囊对自发性高血压大鼠肾胺酶表达的影响

目的:观察地龙降压胶囊对自发性高血压大鼠(SHR)肾胺酶表达的影响,以探讨地龙降压胶囊治疗原发性高血压的作用机制。方法:取24只8周龄雄性SHR,根据收缩压随机分为模型组(等容量蒸馏水灌胃)及地龙降压胶囊高、低剂量组(分别以地龙降压胶囊240mg/kg、120mg/kg灌胃),每组8只。另取8只WKY雄性大鼠作为正常对照组(等容量蒸馏水灌胃)。分别于连续给药前、给药后第2周、4周、6周、8周测定尾动脉收缩压。末次给药后,采用ELISA法检测大鼠血浆儿茶酚胺和血清肾胺酶含量。采用免疫组织化学法检测大鼠肾脏肾胺酶的表达。结果:地龙降压胶囊有效降低了SHR收缩压、血浆儿茶酚胺水平(P<0.05);升高了SHR肾胺酶水平(P<0.05)。结论:地龙降压胶囊能有效降低血压,其作用机制可能是通过调节肾胺酶表达水平,从而影响血浆儿茶酚胺水平实现的。