• 대한약리학회지
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• 제10권2호
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• pp.55-62
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• 1974

This study was undertaken to determine if the adrenocortical hormone was concerned on erythropoietic function, especially on the production of erythropoietin in the kidney. Erythropoietin titers in plasma measured in each group of mice: 1) hypertransfused mice treated with the plasma of rats pretreated with hydrocortisone, dexamethasone, fludrocortisone and DOCA 2) hypertransfused mice treated with the plasma of the rat pretreated with aldosterone antagonist and adrenocortical hormone concomitantly. Erythropoietin level in plasma were measured by the modification of DeGowin's method. The results of the experiment were summerised as follows: 1) No significant changes of erythropoietin titers were observed in hypertransfused mice treated with the plasma of rats pretreated with hyrocortisone and dexamethasone respectively. 2) Erythropoietin titers increased significantly in hypertransfused mice treated with the plasma of rats pretreated with fludrocortisone and DOCA respectively, compared with control. 3) No significant changes of erythropoietin titers were observed in hypertransfused mice treated with the plasma of rats pretreated with spironolactone and triamterene respectively, compared with control. 4) Erythropoietin titers slightly increased in hypertransfused mice treated with the plasma of rats pretreated with spironolactone or triamterene, and fludrocortisone concomitantly and also with spirolactone or triamterene and DOCA.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.9-14
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• 1999

Factors affecting gene gun-mediated expression of the human erythropoietin gene were investigated in primary cultured oviduct cells from laying hens. The human erythropoietin gene was transfected by a gene gun method at $1.25{\mu}g$ per dish, and cultured in a synthetic serum-free medium for 72 hrs. The concentration of human erythropoietin mRNA was determined by RNA : RNA solution hybridization. In experiment 1, the effect of changing the shooting pressure of DNA-coated microparticles with nitrogen gas was tested at 20 and $60kgf/cm^2$. The results showed that the erythropoietin mRNA concentration was significantly higher at 60 than $20kgf/cm^2$. In experiment 2, the effects of supplementing the medium with fetal calf serum at 10%, and raising the shooting pressure from 60 to $80kgf/cm^2$ on the cell number and erythropoietin gene expression were examined. Although supplementation with fetal calf serum significantly increased the cell numbes compared with no supplemented controls (p < 0.05), erythropoietin mRNA concentration per $10^3$ cells was not affected. Raising the shooting pressure from 60 to $80kgf/cm^2$ did not affect either of the parameters, In experiment 3, the effect of supplementing ascorbate 2-phosphate at 0.5 mM was tested. The results indicated that the ascorbate supplementation significantly increased the cell number (p < 0.05), and tended to increase erythropoietin mRNA concentration (p < 0.1). Thus, for human erythropoietin gene expression by using the gene gun method, shooting pressure with nitrogen gas should be sufficient at $60kgf/cm^2$ and supplementation with ascorbate phosphate would be useful to enhance not only the cell proliferation but also erythropoietin gene expression.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.621-626
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• 2006

Purpose: Erythropoietin is traditionally known to regulate erythropoiesis, but recently its protective effect against ischemia-reperfusion injury has been studied mainly in cardiovascular and neuronal systems. This study was planned to investigate the effects of recombinant human erythropoietin on ischemia-reperfusion injury in rat TRAM flap model. Methods: Superiorly based TRAM flap was elevated and ischemic insult was given for four hours. Thirty minutes before reperfusion, single dose recombinant human Erythropoietin(5000IU/kg) was injected via intraperitoneal route in the treatment group. At 24 hours postoperatively, systemic neutrophil count, tissue myeloperoxidase activity, malonyldialdehyde amount, nitric oxide content, tissue water content and histologic finding of inflammation was evaluated. On 10 days postoperatively, flap survival rate, angiogenesis and change in hematocrit level was evaluated. Results: Tissue nitric oxide level was significantly higher and myeloperoxidase activity was significantly lower in the treatment group 24 hours after reperfusion. Tissue water content was significantly lower in the treatment group. Perivascular neutrophil infiltration and intravascular adhesion was marked in the control group. Mean flap survival after ten days was 69% in the treatment group, and 47% in the control group, demonstrating a significant difference. Neovascularization in the treatment group also outnumbered the control group. No significant hematocrit rise was noted ten days after erythropoietin administration. Conclusion: Recombinant human Erythropoietin improved flap survival in ischemia-reperfusion injured rat TRAM flaps, at least partially owing to suppressed inflammation, increased nitric oxide, and enhanced angiogenesis.

• Toxicological Research
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• 제13권1_2호
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• pp.131-138
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• 1997

Group of 40 male and 40 female Sprague-Dawley rats were given daily intravenous injections of different dosage of Erythropoietin (EPO), 80 IU/ kg/day (low dosage group), 400 IU/ kg/day (middle dosage group), or 2000 IU /kg/day (high dosage group)for 4 weeks by tail vein according to Established Regulation of Korean National Institute of Safety Research (1994. 4. 14). Appearance, behavior, mortality, and food consumption of rats of treated groups were not affected during the experimental periods. No significant EPO (erythropoietin)-related changes were found in urinalysts, eye examination, hematology, serum chemistry, and organ weight. No histopathological lesions were observed in both control and treatment groups. Our results strongly suggest that no toxic changes were found in rat treated intravenously with EPO (erythropoietin)for 4 weeks.

• 대한핵의학회지
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• 제9권2호
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• pp.39-46
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• 1975

It is the purpose of this paper to design the most preferable method of erythropoietin bioassay in Korea. Bioassay utilizing polycythemic mice are currently in general use for the indirect determination of erythropoietin. Assay animals are usually prepared either by transfusion or by exposure to reduced oxygen tension in specially constructed chamber. We prepared the polycythemic, mice by the specially constructed hypobaric chamber. We observed weights and hematocrits of the mice in the hypobaric chamber, then hematocrits and 72 hours $^{59}Fe$ red cell upatke ratio of the polycythemic mice induced by hypoxia after removal from the hypobaric chamber. We designed the method of erythropoietin bioassay according to the results obtained by above experiments. Then we measured the 72 hours $^{59}Fe$ red cell uptake ratio of the polycythemic mice with normal saline, normal plasma and anemic plasma according to the method we designed. The results are followed: 1. The hematocrits of the mice in hypobaric chamber increased to 74% in 14 days It is preferable to maintain the pressure of the chamber to 400mmHg for first 4 days then 300mmHg for last 10 days to reduce the death rate and time consuming in hypobaric chamber. 2. After removal from the hypobaric chamber, the 72 hours $^{59}Fe$ red cell uptake ratio decreased rapidly and maintained the lowest level from the fourth day to tenth day. 3. We design the method of erythropoietin bioassay according to the results of above experiment and to the half life of erythropoietin. 4. The Korean product S9Fe is mixture of $^{59}Fe\;and\;^{55}Fe$. And the $^{59}Fe$ red cell uptake ratio in normal mice was far less with Korean product $^{59}Fe$ than with pure $^{59}Fe$ of foreign product. So it is desirable to use pure $^{59}Fe$ in this method of erythropoietin bioassay. 5. Considering the cost, the technique, the time consuming and the sensitivity it is the most preferable method of erythropoietin bioassay in Korea using hypobaric chamber to induce the polycythemia.

• Biomolecules & Therapeutics
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• 제6권1호
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• pp.50-55
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• 1998

Antigenic potential of a recombinant human erythropoietin (rhEPO) produced by Dong-A charm. Co. Ltd. was examined by active systemic anaphylaxis (ASA) test in guinea pigs, mouse-rat passive cutaneous anaphylaxis (PCA) reaction and passive hemagglutination (PHA) test. In ASA test, rhEPO induced the signs of restlessness, rubbing or licking nose, sneezing and coughing in the animals immunized with rhEPO 1000 lU/kg alone or rhEPO 1000 lU/kg incorporated into Freund\\\\`s complete adjuvant. In the mouse-rat PCA test, only one of six sera from the animals immunized with rhEPO 1000 lUng incorporated into Alum showed positive result. In the PHA test, rhEPO revealed negative results in all of the rhEPO-immunized groups. From these results, rhEPO was considered to produce IgE in guinea pigs and mice, but not IgG and/or IsM in mice. The results of this study were similar to those of the other recombinant human erythropoietin and these positive results were thought to be caused due to the fact that rhEPO were heterogeneous proteins to guinea pigs and mice. Considering the fact that rhErO has an identical structure with indigenous human erythropoietin, rhEPO is not thought to cause immunological problems in clinical use.

• The Korean Journal of Physiology and Pharmacology
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• 제14권5호
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• pp.345-352
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• 2010

The present study was undertaken to explore the potential of erythropoietin in memory deficits of mice. Memory impairment was produced by scopolamine (0.5 mg/kg, $i.p.$) and intracerebroventricular streptozotocin (i.c.v STZ, 3 mg/kg, $10{\mu}l$, $1^{st}$ and $3^{rd}$ day) in separate groups of animals. Morris water-maze test was employed to assess learning and memory. The levels of brain thio-barbituric acid reactive species (TBARS) and reduced glutathione (GSH) were estimated to assess degree of oxidative stress. Brain acetylcholinesterase enzyme (AChE) activity was also measured. Scopolamine/streptozotocin administration induced significant impairment of learning and memory in mice as indicated by marked decrease in Morris water-maze performance. Scopolamine/streptozotocin administration also produced a significant enhancement of brain AChE activity and brain oxidative stress (an increase in TBARS and a decrease in GSH) levels. Treatment of erythropoietin (500 and 1,000 IU/Kg i.p.) significantly reversed scopolamine- as well as streptozotocin-induced learning and memory deficits along with attenuation of those-induced rise in brain AChE activity and brain oxidative stress levels. It may be concluded that erythropoietin exerts a beneficial effect in memory deficits of mice possibly through its multiple actions including potential anti-oxidative effect.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.171-178
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• 2000

To evaluate the pharmacokinetic properties and tissue distribution of a newly developed recombinant human erythropoietin (GC-rhEPO), we analyzed the plasma and tissue levels of erythropoietin by an ELISA after intravenous (IV) and subcutaneous (SC) adminstration to the male rats at the doses of 20, 100, 500 or 2,500 unit/kg. After single IV bolus injection of GC-rhEPO, the plasma concentration was rapidly increased and decreased with two phases with half-lives of 13.4 min and 2.94 hours. AUC was increased dose- dependently but plasma half-lives remained constant regardless of GC-rhEPO doses. Following SC administration, the plasma concentration increased slowly with half-life of 9.2 hours and reached peak at 8 hours. Mean residence time and bioavailability were 18.2 hours and 44%, respectively. After single IV dose of 100 unit/kg, tissue GC-rhEPO level was higher in bone marrow and spleen, while the depletion rate was slower in liver and bone marrow, indicating the higher affinity of GC-rhEPO to bone marrow. Taken together, the experimental results indicate that GC-rhEPO contained the typical pharmacokinetic properties and the tissue distribution patterns inherent to human erythropoietin.

• Toxicological Research
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• 제13권1_2호
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• pp.149-152
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• 1997

This test was performed to evaluate the ocular and skin irritation of EPO (Erythropoietin). The results as follows: 1. Ocular irritation test There were no observed clinical signs, body weght changes by EPO during experimental period. The acute ocular irritation index(A.O.I.), mean ocular irritation index(M.O.I.) and Day-7 individual ocular irritation index(I.O.I.) of EPO at dose of 1000U and 10, 000U were 0, respectively. Therefore we evaluated that EPO was non-toxic to eyes. 2. Skin irritation test There were no observed clinical signs, body weght changes and gross pathologic findings by EPO during experimental period. There were no observed erythema, eschar formation and edema formation on intact and abraded skin treated by EPO. The primary irritation index(P.I.I.) of EPO at dose of 1000U and 10, 000U were 0, respectively and were evaluated none irritating product about skin irritation.

• Toxicological Research
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• 제13권1_2호
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• pp.139-147
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• 1997

Four-week toxicity of EPO(erythropoietin) was investigated using New Zealand White rabbits according to the established regulations of Korean National Institute of Safety Research. Rabbits were administered intravenously seven days per week for 28 days with dosage of 0, 80, 400 and 2000IU/kg B. W./day. Animals administered with EPO showed no significant changes of body weight, water consumption and feed consumption, and no clinical signs and death. They were not significantly different from the control group in hematological and serum biochemical analysis, urinalysis, prothrombin time, and partial thromboplastin time. In this study, we concluded that EPO had no toxic effect in the New Zealand White rabbits when they were administered intravenously below 2000IU/ kg B.W./ day for 28 days.