促红细胞生成素对挫裂伤脑组织线粒体的影响

目的 探讨重组促红细胞生成素(rhEPO)对大鼠颅脑损伤后脑线粒体能量代谢以及线粒体呼吸功能的影响.方法 健康雄性SD大鼠63只,随机分为rhEPO治疗组(n=28):以自由落体法制作大鼠腑挫裂伤模型,伤后立即腹腔注射rhEPO 10 U/g,每10 h重复注射1次;对照组(n=28):同样脑挫裂伤模型,伤后立即腹腔注射相同剂量生理盐水;假手术组(n=7):只钻孔不致伤.采用生化检测的方法分别测定治疗组治疗后6 h、12 h、24 h和48 h及各自的对照组大鼠脑组织线粒体ATP酶和SOD的活性和MDA水平以及线粒体呼吸功能.各组数值进行F和t检验.结果 重组促红细胞生成素治疗后12 h、24 h和48 h治疗组大鼠脑组织线粒体ATP酶、SOD活性和呼吸功能均高于各自时间点对照组(P＜0.05,P＜0.01,P＜0.01),而MDA水平则明显低于各自对照组(P＜0.01).结论 重组促红细胞生成素可以通过影响线粒体能量代谢及呼吸功能而减轻大鼠创伤性脑损伤后的继发性脑损害.     

Serum erythropoietin levels in hemodialysed patients after administration of recombinant human erythropoietin.

In anemic patients on regular hemodialysis (HD), correction of anemia with recombinant human erythropoietin (rHuEpo) administered intravenously (iv) or subcutaneously (sc) was followed over a 2-month period. Monitoring serum Epo post-dose concentrations after the first iv rHuEpo injection and following another regular injection after 2 months of therapy with rHuEpo iv in 9 patients showed that the Epo elimination half-life was reduced from 7.48 h to 4.68 h. In the same patients the initially low percentage of erythroblasts and mature erythroid progenitors increased during 2 months of rHuEpo therapy. Because Epo molecules bound to Epo receptors are internalized in target cells we suggest that the expansion of the Epo responsive cell pool could explain the shorted Epo elimination time after 2 months of rHuEpo treatment. By monitoring serum Epo concentration following sc rHuEpo injection in 7 HD patients it was found that the modest increase in serum Epo levels (30-60 mU/ml) was sufficient to correct anemia.     

The effect of recombinant human erythropoietin on neurovasculature repair after focal ischemic stroke in neonatal rats

Cerebral ischemia disrupts the neurovascular unit, involving death of neuronal, glial, and endothelial cells (ECs) in the core and penumbra regions. Whereas the neuroprotective effect of recombinant human erythropoietin (rhEPO) has been widely investigated, its effects on ECs remain elusive. We now report the effects of rhEPO treatment on EC death and neurovasculature repair following a focal ischemic stroke in postnatal day 7 neonatal rats. rhEPO (5000 U/kg i.p.) was administered 60 min after ischemia and for the next 3 days. Western blot analysis revealed increased expression of neurovascular remodeling proteins, including Tie-1, angiopoietin-2, and basic fibroblast growth factor in rhEPO-treated pups. rhEPO treatment significantly reduced EC death in the ischemic penumbra region 12 to 72 h after ischemia examined by immunostaining of terminal deoxynucleotidyl transferase dUTP nick-end labeling and EC marker glucose transporter-1 (GLUT-1). Treatment with rhEPO increased proliferation of ECs and neuronal cells, revealed by costaining of 5-bromo-2'-deoxyuridine with GLUT-1 or with the neuronal marker protein (NeuN) 7 to 21 days after stroke. Specifically, rhEPO increased number of NeuN-positive cells in close proximity to proliferating microvessels. These results suggest for the first time that, in addition to its protection on neural cells, EPO protects ECs and promotes the neurovascular unit repair, which may contribute to its therapeutic benefits after neonatal ischemic stroke.     

Effects of long-term erythropoietin therapy on the hypothalamo-pituitary-testicular axis in male CAPD patients.

OBJECTIVE: Gonadal dysfunction has been recognized for a long time in uremic male patients. The present study assesses the hypothalamo-pituitary-testicular axis and growth hormone status in male continuous ambulatory peritoneal dialysis (CAPD) patients, before and after recombinant human erythropoietin (rHuEPO) therapy. DESIGN: Single-center prospective study. SUBJECTS: Ten anemic male patients with chronic renal insufficiency, and 11 healthy volunteers with normal renal function, matched for age, were included in the study. All patients were on CAPD therapy and none had received rHuEPO treatment previously. MAIN OUTCOME MEASURES: Blood samples were collected between 0800 and 0900 hr from all patients for the determination of basal follicle stimulating hormone (FSH), luteinizing hormone (LH), and growth hormone (GH) levels. A luteinizing hormone-releasing hormone (LH-RH) stimulation test was carried out using LH-RH 100 microg intravenous as a bolus injection. Blood for FSH, LH, and GH determinations was drawn every 30 minutes during the 3-hour test period. Human chorionic gonadotropin (hCG) test was performed after 48 hours. After estimations of basal serum total and free testosterone levels, 2000 IU hCG was administered intramuscularly and repeated 48 hours later. Total and free testosterone levels were measured in blood samples collected before and 48 hours after two injections of hCG. After improvement in anemia with exogenous rHuEPO, LH-RH and hCG tests were repeated. RESULTS: Baseline FSH concentrations before and after rHuEPO treatment were slightly higher in CAPD patients than in healthy volunteers (p = 0.85 and p = 0.70, respectively). Areas-under-the-curve (AUCs) for FSH secretion before and after rHuEPO treatment were also slightly higher in patients than in healthy volunteers (p = 1.00 and p = 0.75, respectively). The pretreatment basal LH levels in patients were significantly higher than in controls (p < 0.001). After the improvement in anemia with rHuEPO, serum LH levels declined significantly (p < 0.05). The AUCs for LH secretion before and after rHuEPO treatment were significantly higher in patients than in controls (p < 0.05). All patients had elevated basal levels of GH with paradoxical response to LH-RH. Baseline GH levels in patients were significantly higher than those in healthy subjects (p < 0.001) before rHuEPO treatment. After treatment with rHuEPO, basal GH levels declined but did not normalize, and baseline levels of free testosterone increased significantly (p < 0.05). CONCLUSION: Anemic uremic male patients on CAPD have normal levels of testosterone with normal response to hCG administration, elevated basal levels of GH, and elevated basal levels of LH, with exaggerated response to LH-RH administration. Improvement in anemia with rHuEPO reduced the basal levels of LH and GH, but exaggerated the LH response; paradoxical GH response to LH-RH administration persisted. These results indicate a defect at the level of the hypothalamus and pituitary gland in uremic male patients undergoing CAPD, and that the improvement in anemia with rHuEPO partially restores some of these endocrine abnormalities.     

A comprehensive study on hemostasis in CAPD patients treated with erythropoietin.

OBJECTIVE: Bleeding diathesis and simultaneous thrombotic complications may be seen in dialyzed patients. Erythropoietin (EPO) may shift the precarious balance of the hemostatic system toward thrombosis. Platelets and tissue factor (TF) play a major role in plug formation. Tissue factor pathway inhibitor (TFPI) appears to play a primary role in regulating TF-induced coagulation. Thrombin activatable fibrinolysis inhibitor (TAFI) is a key protein linking coagulation and fibrinolysis.The aim of the study was to assess whether 6 months of EPO therapy affects platelet function, that is, platelet aggregation and P-selectin level; moieties of the extrinsic coagulation pathway: TF, TFPI, and TFPI/Xa complexes, and factors VII and X; markers of ongoing coagulation: thrombin-antithrombin complexes (TAT) and prothrombin fragments 1+2; a marker of ongoing fibrinolysis: plasmin-antiplasmin complexes (PAP); fibrinolytic activity: euglobulin clot lysis time (ECLT); and markers of endothelial cell injury: von Willebrand factor, thrombomodulin, E-selectin, and TAFI, in continuous ambulatory peritoneal dialysis (CAPD) patients. PATIENTS AND METHODS: 22 patients on CAPD were given EPO 6,000 U/week. 12 patients with chronic renal failure and 12 healthy volunteers served as control groups. All parameters were studied before, and after 1, 3, and 6 months of EPO therapy. SETTING: Department of Nephrology and Internal Medicine, Medical Academy of Bialystok, Poland. RESULTS: Platelet aggregation in whole blood did not change significantly during EPO treatment. A significant rise in arachidonic acid-induced platelet aggregation in platelet-rich plasma was observed after 3 and 6 months, and in collagen-induced platelet aggregation after 6 months of EPO therapy, compared to the baseline values. The TFPI concentration decreased significantly after 6 months of EPO therapy. The activity of factor VII increased transiently after 1 month of EPO therapy, compared to the baseline values. The TAFI concentration and activity in the CAPD group were significantly higher than in the control group. Erythropoietin therapy resulted in a significant decrease in TAFI concentration and activity after 6 months of EPO treatment. The ECLT was shortened significantly as early as after 1 month of EPO therapy. Thrombomodulin, von Willebrand factor concentration and activity, PAP, TAT, TFPI/Xa complexes, prothrombin fragments 1+2, factor X activity, P-selectin, E-selectin, and lipoprotein(a) did not change significantly during EPO treatment. CONCLUSION: Erythropoietin treatment has a minimal effect on hemostasis in CAPD patients. A tendency toward a decline in TAFI is of unknown clinical relevance so far, and awaits further research.     

重组人促红细胞生成素对兔脊髓缺血/再灌注损伤后白细胞介素8表达的影响

目的探讨重组人促红细胞生成素(rHuEPO)对兔脊髓神经细胞缺血/再灌注损伤后白细胞介素8(IL-8)表达的影响。方法 44只健康成年新西兰大白兔随机分为3组:假手术组(4只),对照组(20只),rHuEPO处理组(20只),对照组与rHuEPO处理组分别于再灌注6 h,12 h,24 h、48 h、7 d后时间点随机处死4只动物,取L3～L5节段脊髓组织用霉菌抗生物素蛋白-过氧化酶免疫组化染色法(S-P法)及兔抗人IL-8 ELISA试剂盒检测脊髓组织内IL-8的表达。结果 IL-8在无损伤脊髓中即见有表达。随着缺血及再灌注进程的加重,组织中IL-8阳性表达强度逐渐增加。脊髓损伤后24 h表达明显上调并达高峰;高表达持续至损伤后7 d;两组间IL-8水平的变化趋势相同,但在各时间点rHuEPO处理组兔脊髓组织IL-8的含量均低于对照组(P<0.05)。结论 rHuEPO具有抑制脊髓组织炎症反应的作用,能明显抑制兔脊髓缺血/再灌注损伤后的IL-8表达。     

The effect of human recombinant erythropoietin on iron absorption and hepatic iron in a rat model.

In order to ascertain whether recombinant human erythropoietin (EPO) therapy would result in further intestinal iron absorption in the setting of systemic iron loading, iron absorption was measured in iron-loaded rats receiving EPO therapy and a control group of iron-loaded rats. Parenteral iron dextran (100 mg) resulted in hepatic siderosis with predominantly a reticuloendothelial distribution. EPO was given by intraperitoneal injection (100 U/kg) for 10 days. Radioiron absorption was measured by total body counting. Iron absorption in EPO-treated rats was 4.8 +/- 2.0% (n = 12) and 4.5 +/- 2.2% (n = 10) in the control rats (p greater than 0.05). Mean hemoglobin in the EPO rats was 201 +/- 12.5 g/L and 140 +/- 18.2 g/L in the control rats (p less than 0.001). Mean hepatic iron concentration was 73 +/- 16 mumol/g in the control rats and 34 +/- 9.1 mumol/g in the EPO-treated rats (p less than 0.001). This study suggests that iron-loaded rats do not demonstrate an increase in intestinal iron absorption with EPO therapy despite a significant erythropoiesis. The reduction in hepatic iron concentration suggests that reticuloendothelial iron is accessible and mobilized to produce new red blood cells.     

The effect of treatment with human recombinant erythropoietin on the functional status of patients on maintenance hemodialysis

As many as ten patients with terminal uremia on maintenance hemodialysis (MH) performed from 11 to 52 months (28 +/- 4 on the average) were treated with recombinant human erythropoietin (rhERP) manufactured by Cilag (Switzerland). The preparation was injected i.v. in the initial dose 65 U/kg bw thrice a week after each session of MH. If the effect was lacking for 2 weeks, the doze was augmented by 25 U/kg (maximally up to 218 U/kg). Provided the Hb content increased to 100-120 g/l, the maintenance therapy was initiated (108 +/- 13 U/kg). The treatment lasted 17 +/- 2 weeks. As a result, the Hb content in the patients rose from 63.0 to 102.0 g/l, the hematocrit index from 21.2 to 34.4%, the red blood cell count from 2.09 to 3.18 x 10(12)/l; there was a transitory increase of the reticulocyte and platelet counts (from 2.2 to 3.3% and from 172.0 to 284.0 x 10(9)/l) whereas the leukocyte count remained unchanged. It has been demonstrated by the bicycle ergometry data that in addition to the amelioration of the hematological parameters, the patients showed an increase of oxygen consumption at rest, rise of the economy of energy losses at exercise, and a decline of oxygen "cost" of work. According to echocardiography, the patients manifested a reduction of the size of the left heart, of the minute and stroke volumes. In men, the treatment with rhERP brought about libido elevation in the absence of significant alterations in the blood gonadotrophin and testosterone concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intraperitoneal administration of recombinant human erythropoietin.

OBJECTIVE: To determine the efficacy and safety of intraperitoneal administration of recombinant human erythropoietin (rHuEPO) in continuous ambulatory peritoneal dialysis (CAPD) patients compared to subcutaneous rHuEPO. DESIGN: Prospective analysis of an open, nonrandomized investigation. SETTING: Outpatient CAPD clinics in two university hospitals. PATIENTS: Nine adult CAPD patients receiving rHuEPO intraperitoneally and 8 patients receiving rHuEPO subcutaneously. INTERVENTION: One hundred units of rHuEPO per kilogram of body weight were administered three times a week for 8 weeks or until the target hematocrit of 35% was reached. Thereafter, dosages of rHuEPO were adjusted for response. Intraperitoneal rHuEPO was administered in 1 L of dialysis solution during the night. MEASUREMENTS: Efficacy was assessed by measuring the increase in hemoglobin. Tolerance was assessed by monitoring side effects. RESULTS: In the first 8 weeks of treatment hemoglobin concentration increased from 64.5 +/- 12.9 g/L to 98.3 +/- 16.1 g/L (p < 0.0005) in the intraperitoneally treated group. In the subcutaneously treated group hemoglobin increased significantly faster (p < 0.05) from 72.5 +/- 4.8 g/L to 119.2 +/- 11.3 g/L (p < 0.0005) in the same period. Antihypertensive medication had to be increased or instituted in most of the patients in both groups. The incidence of peritonitis in the intraperitoneally treated group was not increased when compared to the pretreatment incidence. CONCLUSIONS: Subcutaneously administered rHuEPO is superior to intraperitoneally administered rHuEPO with regard to the required dosages. However, the results of this study show that intraperitoneal administration of rHuEPO might be a convenient and safe alternative when subcutaneous administration is undesirable.     

红细胞生成素对骨髓源间充质干细胞迁移的影响

目的 利用Transwell体外迁移体系初步探索EPO在骨髓源间充质干细胞(MSC)迁移中的作用及其信号传递机制.方法 采用经典的全骨髓细胞贴壁法培养MSC,通过成骨、成脂肪等多向诱导分化以及流式细胞术分析其表面标志(CD133、CD34、CD90、CD105)等鉴定MSC特征;以第3代MSC为实验材料,利用Transwell体外迁移体系,先观察不同浓度的rhEPO对MSC迁移的影响,随后在50 nmol/L Wortmannin、50μmol/L PD98059、10μmoL/L U73122、4μg/ml抗EPO-R IsG、30 μmol/LSB203580、10 mmol/L Straurosporine、6 nmol/L G0697、50 μmol/L Pseudo Z等不同的信号转导途径阻断剂的干预下观察EPO对迁移的影响.结果 培养的MSC呈现出CD90、CD105强阳性,具有成骨、成脂肪等多向分化能力;MSC体外迁移能力随着rhEPO浓度(1、10、100、1000 IU/ml)的递增而逐渐增强,并且rhEPO浓度在100 U/ml时,MSC迁移到滤膜上的细胞数接近于峰值;Wortmannin、PD98059、抗EPO-R IgG、Straurosporine、G06976、Pseudo Z对MSC迁移均有影响,其中U73122、抗EPO-R IgG、Straurosporine、Pseudo Z对MSC迁移阻断的效应最显著.结论 EPO-EPO-R所介导的MSC迁移与丝裂原活化蛋白激酶、磷脂酰肌醇特异性磷脂酶C和蛋白激酶C-ζ(PKC-ζ)等信号传递途径有关,且PKC-ζ途径可能处于中心环节.     

Immediate initiation of CAPD following percutaneous catheter placement without break-in procedure.

OBJECTIVE: To evaluate the effect of a modified method of percutaneous catheter placement without a break-in procedure on the development of catheter-related complications in patients on continuous ambulatory peritoneal dialysis (CAPD). DESIGN: A prospective, observational clinical study. SETTING: Peritoneal dialysis (PD) units of two university-based hospitals. PATIENTS AND METHODS: This study included 51 consecutive patients on CAPD. A straight double-cuffed Tenckhoff catheter with a straight intraperitoneal segment was used, and all catheters were inserted using a modified percutaneous placement method under local anesthesia. The catheter was introduced directly into the deep pelvis through an intramuscular tract, which had been created by tapered dilators. Peritoneal dialysis was initiated immediately after catheter insertion without a break-in procedure. Catheter-related complications were surveyed during the 12 months after initiation of CAPD. RESULTS: Within the first month, only 1 pericatheter leakage (1.9%) was detected. There were no cases of visceral perforation or severe hemorrhage during catheter insertions. Catheter malfunction due to catheter tip migration, exit-site infection, and peritonitis developed in only 1.9%, 3.9%, and 3.9% of patients, respectively. After 1 month following catheter insertion, no further incidences of pericatheter leakage occurred during the follow-up period. All catheters, except one that was reinserted due to tip migration, survived throughout the study period. CONCLUSION: The rates of pericatheter leakage and other catheter-related complications are relatively low in CAPD patients using our percutaneous catheter placement method without a break-in procedure. This procedure is comparatively simple and less invasive than other catheter placement methods, and allows for immediate start of PD after catheter insertion, without a break-in procedure.     

重组人促红细胞生成素对大鼠脊髓损伤后脂质过氧化的影响

目的：观察重组人促红细胞生成素对大鼠脊髓损伤后脂质过氧化和超微结构改变的影响。 方法：实验于2004-05／08在吉林大学第二医院中心实验室完成。选择健康成年SD大鼠27只，采用改良Allen’s法制作脊髓损伤模型。27只SD大鼠随机数字表法分为3组：治疗组（H=9）：造模后立刻给予重组人促红细胞生成素腹腔内注射（5000U／kg）1次；生理盐水对照组（n=9）：造模后立刻给予等量生理盐水腹腔内注射1次。正常组（n=9）：不作任何处置。采用硫代巴比妥酸法检测脊髓损伤后2，24，48h丙二醛含量变化，使用透射电镜技术评估脊髓损伤后各时相点的超微结构评分。 结果：纳入大鼠27只，均进入结果分析。①生理盐水对照组和治疗组伤区丙二醛含量随伤后时间的增加呈不断升高的趋势，生理盐水对照组伤后2，24，48h伤区丙二醛含量较正常组明显增加，差异有显著性意义[分别为（92．45&;#177;6．22），（65．62&;#177;2．22）nmol／g；（112．56&;#177;6．68），（68．20&;#177;1．84）nmol／g；（142，38&;#177;7．24），（66．40&;#177;2．04）nmol／g，P〈0．05]。治疗组伤后2，24，48h丙二醛含量较生理盐水对照组明显降低[分别为（68．54&;#177;5．88），（92．45&;#177;6．22）nmol／g；（75．24&;#177;6．28），（112．56&;#177;6．68）nmol／g．P〈0．05；（88．34&;#177;8．52）．（142．38&;#177;7．24）nmol／g，P〈0．01]。②生理盐水对照组的超微结构评分随伤后时间的增加呈不断升高的趋势，而治疗组的超微结构评分随伤后时间的增加则变化不大，相对稳定。治疗组伤后2，24，48h的超微结构评分均较生理盐水对照组明显降低，差异有显著性意义[分别为（1.28&;#177;0．45），（3．84&;#177;0．25）分；（1．38&;#177;0．28），（4．24&;#177;0，38）分；（1．42&;#177;0．36），（4．98&;#177;0．52）分，P〈0．05]。 结论：重组人促红细胞生成素能够明显降低脊髓损伤后丙二醛含量，减轻脊髓损伤后的脂质过氧化，显著降低脊髓损伤后的超微结构评分，明显减轻脊髓损伤后的超微结构改变，有效地保护脊髓组织，具有明显的神经保护作用.     

重组人促红细胞生成素对大鼠脊髓损伤后脂质过氧化的影响

目的:观察重组人促红细胞生成素对大鼠脊髓损伤后脂质过氧化和超微结构改变的影响。方法:实验于2004-05/08在吉林大学第二医院中心实验室完成。选择健康成年SD大鼠27只,采用改良Allen’s法制作脊髓损伤模型。27只SD大鼠随机数字表法分为3组:治疗组(n=9):造模后立刻给予重组人促红细胞生成素腹腔内注射(5000U/kg)1次;生理盐水对照组(n=9):造模后立刻给予等量生理盐水腹腔内注射1次。正常组(n=9):不作任何处置。采用硫代巴比妥酸法检测脊髓损伤后2,24,48h丙二醛含量变化,使用透射电镜技术评估脊髓损伤后各时相点的超微结构评分。结果:纳入大鼠27只,均进入结果分析。①生理盐水对照组和治疗组伤区丙二醛含量随伤后时间的增加呈不断升高的趋势,生理盐水对照组伤后2,24,48h伤区丙二醛含量较正常组明显增加,差异有显著性意义[分别为(92.45±6.22),(65.62±2.22)nmol/g;(112.56±6.68),(68.20±1.84)nmol/g;(142.38±7.24),(66.40±2.04)nmol/g,P<0.05]。治疗组伤后2,24,48h丙二醛含量较生理盐水对照组明显降低[分别为(68.54±5.88),(92.45±6.22)nmol/g;(75.24±6.28),(112.56±6.68)nmol/g,P<0.05;(88.34±8.52),(142.38±7.24)nmol/g,P<0.01]。②生理盐水对照组的超微结构评分随伤后时间的增加呈不断升高的趋势,而治疗组的超微结构评分随伤后时间的增加则变化不大,相对稳定。治疗组伤后2,24,48h的超微结构评分均较生理盐水对照组明显降低,差异有显著性意义[分别为(1.28±0.45),(3.84±0.25)分;(1.38±0.28),(4.24±0.38)分;(1.42±0.36),(4.98±0.52)分,P<0.05]。结论:重组人促红细胞生成素能够明显降低脊髓损伤后丙二醛含量,减轻脊髓损伤后的脂质过氧化,显著降低脊髓损伤后的超微结构评分,明显减轻脊髓损伤后的超微结构改变,有效地保护脊髓组织,具有明显的神经保护作用。     

Study of the actions of human recombinant erythropoietin on rat renal haemodynamics.

1. Studies were undertaken to examine the effect of acute and chronic administration of human recombinant erythropoietin on kidney cortical and papillary perfusion in the anaesthetized rat using laser-Doppler flowmetry. 2. Thirty minutes after erythropoietin (50 and 150 units/kg intravenously), blood pressure, cortical perfusion and papillary perfusion were unchanged. 3. In animals treated chronically with erythropoietin over 7 days (three doses of 150 units/kg subcutaneously) blood pressure was similar to that of vehicle-treated animals, whereas cortical perfusion and papillary perfusion were reduced by 23% and 20%, respectively (both P < 0.05), and the packed cell volume (51.1 +/- 0.7%) was significantly (P < 0.01) greater than in vehicle-treated animals (46.2 +/- 0.6%). 4. Bolus doses of vasopressin and phenylephrine increased blood pressure (by between 10% and 40%) and decreased cortical and papillary perfusion (by between 10% and 20%), while angiotensin II caused similar increases in blood pressure and decreases in cortical perfusion but not papillary perfusion. The magnitude and pattern of these responses were comparable after both acute and chronic administration of erythropoietin. 5. Erythropoietin given acutely at therapeutic levels has a marginal effect on cortical and papillary perfusion. However, the chronic treatment indicated that there was a sustained reduction in both cortical and papillary perfusion, reflecting a vasoconstriction. This reduction in renal haemodynamics could contribute to the increase in blood pressure observed when this hormone is administered in man.