Volume Status in Patients on Peritoneal Dialysis: The Role of Apelin and Bio-Impedance Spectroscopy

One of the main factors determining the survival of peritoneal dialysis (PD) patients is volume status. We aimed to investigate hydration status of PD patients by bio-impedance spectroscopy (BIS) and echocardiography and to study the relation of them with apelin, which has effects related with volume status like vasodilation, positive inotropism, and inhibition of ADH release and RAS antagonism. Chronic PD patients without active cardiac disease or clinically prominent hypervolemia were included. Besides the demographic, clinical, and laboratory data, BIS and echocardiographic findings together with apelin levels were recorded. The study included 21 patients. Of them, eight patients were euvolemic, one patient was hypovolemic, and others have some degree of overhydration (1.1–6.8 L) with BIS, although all were euvolemic clinically. Mean apelin level was 1.49 ± 0.49 ng/mL. Apelin level was positively correlated with ejection fraction and negatively with total body water (TBW), intracellular and extracellular water, lean tissue mass, and left atrium diameter. On linear regression model, TBW was the major determinant of apelin. Although apelin is expected to increase in hypervolemic patients, the negative correlation with body water in this study may be related with yet unknown role of apelin in dialyzed patients. They may have important roles in volume status in future.     

The effects of water immersion and restraint stress on the expressions of apelin,apelin receptor (APJR) and apoptosis rate in the rat heart

Apelin has been identified as an endogenous ligand of the orphan G-protein-coupled apelin receptor (APJR). These receptors are widely expressed in the central nervous system and periphery and play a role in the regulation of fluid and glucose homeostasis, feeding behavior, vessel formation, cell proliferation and immunity. We aimed to investigate whether water immersion and restraint stress have effects on apelin and APJR expression and apoptosis in heart tissue of male Wistar rats. The cardiac tissues were obtained from control, water immersion and restraint stress (WIRS) and apelin antagonist (F13A) + WIRS groups of rats and embedded in paraffin wax. Immunohistochemical staining methods were used to localize apelin, APJR and TUNEL immunopositive cells. H-SCORE was used for semi-quantitative determinations. Apelin protein levels were determined by Western blot in the cardiac tissues and plasma corticosteroid levels were measured by enzyme immunoassay (EIA). Apelin immunolocalization was found especially in endothelial cells and mast cells and faintly in cardiomyocytes, APJR immunostaining was shown in endothelial cells and cardiomyocytes, and TUNEL reaction was observed in endothelial cells and in some fibroblasts. Apelin expression was significantly increased in the WIRS and F13A + WIRS groups compared to the control group. The APJR reaction was similar in all groups. The number of TUNEL-positive cells was significantly higher in the F13A + WIRS group than that of the control group. Our study showed that WIRS for 6 h increased plasma corticosterone levels and cardiac apelin expression in rats. The increased levels of apelin inhibited stress-induced apoptosis in heart. These results may be important for the therapeutic approach to a variety of stress-related heart disease.     

自体骨髓单个核细胞移植治疗后重度缺血性心力衰竭患者血浆Apelin水平变化及其临床意义

目的研究骨髓单个核细胞(BMMC)移植治疗前后缺血性心力衰竭(IHF)患者血浆Apelin水平及心功能的变化。方法纳入40例IHF患者,分为自体骨髓单个核细胞(BMMC)移植组(n=20)及常规治疗组(n=20),分别行BMMC移植及内科常规治疗,另选择20例心功能正常者作为健康对照组。检测各组血浆Apelin、脑钠肽(BNP)基线水平及两组IHF患者经治疗后的血浆Apelin、BNP水平。两组IHF患者治疗前后行超声心动图检查。结果治疗前,与健康对照组比较,BMMC移植组和常规治疗组患者血浆Apelin基线水平均显著降低(P<0.01),血浆BNP基线水平均显著升高(P<0.01),而两组IHF患者间差异无统计学意义(P>0.05)。BMMC移植组移植后患者NYHA分级降低,24h尿量增多,常规治疗组无明显变化。BMMC移植组治疗后7d,患者血浆Apelin水平较基线水平明显升高(P<0.05),21d则显著升高(P<0.01);常规治疗组患者血浆Apelin水平治疗前,治疗后72、1d差异无统计学意义(P>0.05)。7d时BMMC移植组患者血浆Apelin水平高于常规治疗组(P<0.05),21d这种差异则更加显著(P<0.01)。BMMC移植组治疗后7d,患者血BNP水平与移植前比较明显下降(P<0.05),21d时仍明显降低(P<0.05),而常规治疗组患者血浆BNP水平治疗前、治疗后7d和治疗后21d差异无统计学意义(P>0.05)。7d和21d时BMMC移植组患者血浆BNP水平均低于常规治疗组(P<0.05)。结论经BMMC移植治疗后重度IHF患者心功能明显改善,Apelin升高可能是这种改善的重要效应。     

Therapeutic Benefit and Gene Network Regulation by Combined Gene Transfer of Apelin,FGF2, and SERCA2a into Ischemic Heart

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全反式维甲酸对高血压大鼠体内apelin-APJ信号系统的影响

目的:探讨全反式维甲酸(atRA)对高血压大鼠体内心血管活性多肽apelin及其受体APJ信号的影响。方法:采用12周龄雄性自发性高血压大鼠(SHR)及其同源对照WKY大鼠,经腹腔注射atRA,为期1月。分别用实时荧光定量多聚酶链式反应(PCR)与免疫印迹技术测定atRA治疗后SHR体内apelin和APJ受体的表达情况。结果:与WKY对照组相比,SHR心脏组织中apelin及其受体APJ的 mRNA和蛋白表达明显下调(P均<0.01)。而atRA治疗后SHR(低、高剂量atRA组)大鼠心脏组织中apelin、APJ表达出现上调(P均<0.05)。结论:长期atRA治疗促进SHR大鼠心脏组织中apelin及其受体APJ的表达增加,提示转录调节剂atRA很可能对人类高血压病防治具有积极作用。     

正常人群血浆脂肪源性因子水平与体质量的相关性

目的 探讨正常人群血浆脂肪源性因子水平与体质量的相关性.方法 将80名健康志愿者根据2012年世界卫生组织制定的肥胖诊断标准分为超重/肥胖组（41名）和正常体质量组（39名）,分别检测空腹血浆脂肪源性因子、血压水平及体质量指数.结果 超重/肥胖组血浆脂肪源性因子水平、收缩压、舒张压及体质量指数均显著高于正常体质量组（P＜0.01）.偏相关分析显示,血浆脂肪源性因子与体质量指数呈正相关（r=0.253,P＜0.05）.结论 体质量指数增高可能是引起血清脂肪源性因子水平升高的主要因素.     

Clinical significance of apelin in the treatment of type 2 diabetic peripheral neuropathy

Background:Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. As apelin is an adipocytokine closely associated with diabetes, this study explored the clinical significance of serum apelin levels in patients with type 2 DPN before and after treatment.Methods:In total, 44 patients with T2DM without DPN (non-DPN group), 41 patients with DPN who received antihyperglycemic treatment (DPN-A group), 44 patients with DPN who received antihyperglycemic treatment combined with nutritional neurotherapy (DPN-B group), and 40 healthy control individuals (NC group) were selected continuously enrolled in the present study. Enzyme-linked immunosorbent assays (ELISA) were performed to determine serum levels of apelin and tumor necrosis factor-α (TNF-α). Related apelin, fasting blood glucose (FBG), glycosylated hemoglobin A1c, TNF-α, body mass index, fasting C peptide, and nerve conduction velocity (NCV) were recorded in each group before and after treatment.Results:Serum levels of apelin and TNF-α were higher in patients with diabetes than those in the NC group, as well as in the DPN group as compared to the non-DPN group; furthermore, some NCV values were significantly reduced in the DPN group. After treatment, the serum levels of apelin, TNF-α, and FBG reduced in patients with diabetes; moreover, apelin levels were found significantly lower in the DPN-B group as compared to the DPN-A group, while some NCV values significantly increased in the DPN-B group. Apelin was negatively correlated with part of NCV values and positively correlated with TNF-α and FBG (P < .01).Conclusion:Our results show that the increase in serum apelin levels is an important clinical reference index for DPN, while a decrease indicates that the DPN treatment is effective.