老年血液透析患者血压升高的机制及促红细胞生成素的影响

目的　探讨老年血液透析患者血压升高的机制以及基因重组促红细胞生成素(rHuEPO ,EPO)对维持性血液透析患者血管活性介质的影响。　方法　 5 2例老年血液透析患者 ,合并高血压者 2 3例 (HBP组 ) ,正常血压者 2 9例 (NBP组 )。检测血中血管活性介质 :内皮素 (ET)、肾素活性 (PRA)、醛固酮 (PA)、血管紧张素Ⅰ (AⅠ )、血管紧张素Ⅱ (AⅡ )、多巴胺 (DA)、肾上腺素 (E)和去甲肾上腺素 (NE)。NBP组中 15例静脉 1次注射EPO 30 0 0U(EPO组 ) ,14例作为对照 (NS组 )静脉注射生理盐水。均于注射后第 1、3、6、9、12、18、2 4、30、4 4h动态检测血中EPO和上述血管活性介质。　结果　 (1)与NBP组较比 ,HBP组DA (346 0 6± 137 12 )pmol/L、E (6 0 0 0 0± 4 36 36 )pmol/L和NE(4789 90± 1892 31)pmol/L明显增加 (P <0 0 5 ) ;(2 )与NS组相比 ,EPO组ET一过性升高 ,而DA、E和NE进行性升高 (P >0 0 5 )。　结论　老年血液透析患者血压升高和EPO引起的血压升高的机制可能与血中DA、E和NE增多有关。     

促红细胞生成素对实验性肾性贫血的作用

促红细胞生成素(erythropoietin,EPO)是由肾细胞分泌的一种糖蛋白激素。从人胚肾细胞中诱导,经生物化学方法分离、提纯得到此品。本试验用5/6肾切除的方法造成大鼠慢性肾衰性(CRF)贫血,研究不同剂量EPO对CRF贫血的作用。结果表明EPO有显著的促进红细胞生成,改善CRF贫血状态,使其接近或达到正常水平,最佳剂量为1000 U/kg,并可预防实验性贫血,对正常鼠未见明显作用。     

Potential role of protein kinase C on the differentiation of erythroid progenitor cells

The effect of protein kinase C inhibitors, staurosporine and 1-(5-isoquinolinyl sulfonyl)-2-methyl piperazine(H7) onin vitro differentiation of erythroid progenitor cells which were isolated from spleens of mice infected with the anemia-inducing strain of Friend virus were examined. Erythropoietin-mediated differentiation of erythroid progenitor cells, as determined by the incorporation of⁵⁹Fe into protoporphyrin, was inhibited by staurosporine and H7 in a concentration-dependent manner. Scatchard analysis of the³H-phorbol-12, 13-dibutyrate binding to erythroid progenitor cells revealed that at the high affinity sites the dissociation constant was 22nM and the maximum number of³H-phorbol-12,13-dibutyrate binding sites per cell was approximately 3.7×10⁵. Cytosolic protein kinase C was isolated from erythroid progenitor cells and then purified by sequential column chromatography. Two isoforms of protein kinase C were found. Photoaffinity labeling of the purified protein kinase C samples with³H-phorbol 12-myristate 13-acetate followed by analysis of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and autofluorography showed radiolabeled 82-KDa peptides. Radiolabeling of the 82-kDa peptides with³H-phorbol 12-myristate 13-acetate was almost completely blocked by excess unlabeled phorbol 12-myristate 13-acetate. Results of phorbol 12-myristate 13-acetate-promoted phosphorylation with the purified protein kinase C samples showed that the phosphorylation of 82-kDa peptides was increased as the concentration of phorbol 12-myristate 13-acetate was increased from 10⁻⁸ M to 10⁻⁴M. In light of the findings that erythroid progenitor cells possessed an abundance of protein kinase C and that staurosporine and H7 inhibited erythroid differentiation, it seemed likely that protein kinase C would play a role in the erythroid progenitor cell development.     

运动性贫血发病机理的研究

分析了17～21岁耐力运动员181人(男89,女92)和非运动员160人(男82,女78)的血浆睾酮、促红细胞生成素、微量元素铜、锌、及铁、铁蛋白和运铁球蛋白水平,以探讨运动性贫血的发病机制。结果:1.运动员中低于贫血标准的万5人(5.6%)、女7人(7.6%),低于亚理想血红蛋白值的男12人(13.5%)、女18人(19.6%)。2.运动员睾酮水平升高,亚理想血红蛋白组则降低,运动员Epo升高,贫血者更明显。3.运动员血清铜含量下降,贫血者尤为明显。4.运动员的血清铁及铁蛋白水平低于非运动员,其中非贫血者的血清铁在正常范围,但铁蛋白水平亦明显低于非运动员。认为耐力运动员补充铁、铜可防治运动性贫血。     

Inverse relationship between serum erythropoietin and blood lead concentrations in Kathmandu tricycle taxi drivers

Objective Kathmandu tricycle taxi drivers, whose environmental lead (Pb) exposure is ascribable mainly to vehicular exhaust, were studied to examine a dose-response relationship between blood Pb (Pb-B) and serum erythropoietin (sEPO) concentrations. Methods Subjects were 27 drivers and 9 non-drivers. They were non-anemic healthy men with normal renal function. Pb-B was measured by an atomic absorption spectrometer with a graphite furnace, and sEPO was determined with a sandwich-type enzyme-linked immunosorbent assay. Results sEPO levels in drivers were lower than those of non-drivers, while Pb-B levels in drivers were higher than those of non-drivers. There was an inverse relationship between Pb-B and sEPO. Conclusions The data suggest that Pb inhibits renal EPO production in a dose-dependent manner in persons with subclinical Pb toxicity. sEPO may serve as an early biochemical marker of subclinical Pb toxicity.     

Activity of Erythropoietin and Renin in Renal Venous Blood of Hypertensive Patients

Plasma activities of renin and erythropoietin were determined in the renal veins of the right and left kidneys of hypertensive patients. The patients were divided into the following groups either according to the origin of the hypertension (group 1: control or essential hypertension, group 2: renovascular hypertension) or according to the hormone levels (group 3: renin activity exceeding 10 ng/litre in at least one of the renal veins and group 4: erythropoietin activity higher than 4% 5 9Fe incorporation in at least one of the renal veins). In groups 1, 2 and 3 a statistically significant difference in renin activity was found between the kidney with the higher renin activity and that with the lower activity However, in group 4, the side, which showed elevated erythropoietin values also had higher renin activity as compared to the essential hypertensive group. Erythropoietin activity probably does not parallel the increased renin activity found in renovascular hypertension or in some cases of non-renovascular hypertension. However, in several cases of renal vascular alterations, both systems can be activated simultaneously.     

促红细胞生成素对大鼠心肌缺血-再灌注心律失常的影响

目的:观察促红细胞生成素(erythropoietin,EPO)对大鼠心肌缺血-再灌注心律失常的影响并探讨其作用机制。方法:采用结扎左冠状动脉前降支30min再灌注120min的方法建立大鼠心肌缺血-再灌注损伤模型。将60只SD大鼠随机分为3组(假手术组、缺血-再灌注组、EPO治疗组)。连续监测肢体Ⅱ导联心电图记录再灌注心律失常情况;测定再灌注末心肌组织丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、Na+-K+-ATP酶和Ca2+-ATP酶的变化。结果:EPO降低再灌注室性心律失常的发生率与持续时间,使心律失常评分显著降低;EPO减少再灌注末心肌MDA含量,提高心肌GSH-Px、CAT、Na+-K+-ATP酶和Ca2+-ATP酶的活性,对心肌SOD活性无影响。结论:EPO具有抗心肌缺血-再灌注室性心律失常的作用,其机制可能与减轻氧自由基及钙超载的损害有关。     

EPO通过激活PI3K/Akt途径上调HSP70的表达对低温下心衰大鼠起保护作用

目的:评价红细胞生成素(erythropoietin,EPO)对低温环境下心衰大鼠的影响,探讨其可能的作用机制。方法:80只SD大鼠随机分5组,分别为对照组(CON组)、心衰低温组(HFLT组)、心衰常温组(HFNT组)、心衰低温EPO组(HFLT+EPO组)和心衰低温LY294002组(HFLT+EPO+LY组)。然后将所有大鼠放置于气候箱中(CON、HFLT、HFLT+EPO和HFLT+EPO+LY组为低温环境;HFNT组为常温)。超声心动图检测各组大鼠心功能,然后处死大鼠并留取心脏标本,TUNEL法测心肌细胞凋亡,荧光定量PCR测心肌组织中Fas和PI3K mRNA的表达,Western blot测大鼠心肌组织中热休克蛋白70(HSP70)、Akt和p-Akt的水平。结果:低温下心衰大鼠心功能明显低于常温下心衰大鼠,HFLT+EPO组大鼠心功能较HFLT组明显改善,给予LY294002干预后HFLT+EPO+LY组大鼠心功能明显低于HFLT+EPO组;HFLT组及HFNT组凋亡指数均高于CON组(P0.01),HFLT组凋亡指数又明显高于HFNT组(P0.05),HFLT+EPO组凋亡指数明显低于HFLT组(P0.01)。Fas mRNA在HFLT组心肌组织中的表达明显高于HFNT组,PI3K mRNA在HFLT组和HFNT组心肌组织中的表达差异无统计学显著性,HFLT+EPO组心肌组织中Fas的mRNA表达明显低于HFLT组(P0.01)和HFLT+EPO+LY组(P0.05),而PI3K的mRNA表达则明显高于HFLT组和HFLT+EPO+LY组(P0.05)。HFLT+EPO组大鼠心肌组织中p-Akt和HSP70的水平明显高于HFLT组和HFLT+EPO+LY组(P0.05),CON、HFLT和HFNT组大鼠心肌组织中p-Akt和HSP70的蛋白水平差异无统计学显著性。所有大鼠心肌组织中Akt的水平差异无统计学显著性。结论:EPO活化PI3K/Akt后,上调内源性保护途径中HSP70的表达并抑制细胞凋亡,从而对低温下的心衰大鼠心脏起保护作用。     

促红细胞生成素对大鼠坐骨神经损伤后炎性反应和细胞凋亡的影响

目的 探讨促红细胞生成素(EPO)对大鼠坐骨神经损伤后炎性反应和细胞凋亡的影响及其作用机制,为周围神经损伤的临床治疗提供实验依据.方法 雌性SD大鼠36只,制备大鼠左侧坐骨神经缺损模型,随机分为3组,即EPO组、神经生长因子(NGF)组和生理盐水(NS)组.EPO组、NGF组和NS组分别于术后立即及每日腹腔注射FPO、NGF和NS.术后7、14 d,HE染色光镜下观察L5背根神经节细胞形态变化;应用RT-PCR检测损伤近、远端坐骨神经IL-6和TNF-α mRNA的表达;以TUNEL法检测L5背根神经节细胞凋亡.结果 术后7、14 d,EPO组近、远端坐骨神经IL-6mRNA表达低于NS组,差异有统计学意义(P＜0.01);EPO组远端坐骨神经IL-6 mRNA表达低于NGF组,差异有统计学意义(P＜0.01).术后7d,EPO组近、远端坐骨神经TNF-α mRNA表达低于NS组和NGF组,差异有统计学意义(P＜0.01);术后14 d,EPO组远端坐骨神经TNF-α mRNA表达低于NS组,差异有统计学意义(P＜0.05).术后7、14 d,EPO组凋亡细胞数低于NS组,差异有统计学意义(P＜0.01);术后14 d,EPO组凋亡细胞数低于NGF组,差异有统计学意义(P＜0.05).结论 EPO可能通过减少致炎因子IL-6和TNF-α释放,减轻炎性反应,抑制细胞凋亡,对大鼠坐骨神经损伤发挥保护作用.     

不同培养体系对脐血造血干细胞粒细胞-巨噬细胞集落形成单位的影响

目的比较H4534与GF-H4434两种甲基纤维素培养基对脐血生成粒细胞-巨噬细胞集落形成单位（CFU-GM）的影响。方法从新鲜脐血标本中分离出造血干细胞,接种于H4534和GF—H4434培养基,于37℃、5％二氧化碳饱和湿度条件下培养14—16d。结果在样本中CD34＋细胞百分率和有核细胞总数检测结果相似的情况下,H4534与GF—H4434培养条件下CFU-GM集落数分别为（55．71±28．24）／105与（66．28±31．99）／105,两者比较差异有统计学意义（u=4．16,P〈0．05）。GF-H4434培养条件下还产生了红细胞爆裂型集落形成单位（64．89±34．95）／105和粒细胞-红细胞-巨噬细胞-单核细胞集落形成单位（2．53±2．08）／105。结论GF—H4434甲基纤维素培养基中脐血样本CFU-GM集落形成能力更强,更适合脐血质量鉴定。