scholarly journals The in vivo metabolism of recombinant human erythropoietin in the rat

Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 90-99
Author(s):  
JL Spivak ◽  
BB Hogans
Keyword(s):  
Recombinant Human Erythropoietin ◽  
Plasma Clearance ◽  
Dextran Sulfate ◽  
Volume Of Distribution ◽  
Human Albumin ◽  
Recombinant Erythropoietin ◽  
Elimination Phase ◽  
Human Erythropoietin ◽  
Distribution Phase

We compared the in vivo plasma clearance and organ accumulation in anesthetized rats of 125I-labeled, recombinant human erythropoietin and 125I-labeled, desialylated recombinant erythropoietin. The immediate volume of distribution of 125I-labeled, recombinant erythropoietin approximated that of the plasma volume. Its plasma clearance was multiexponential, with an initial rapid distribution phase (t1/2 = 53 minutes) and a slower elimination phase (t1/2 = 180 minutes). Organ accumulation of labeled recombinant erythropoietin, as compared with 125I-labeled human albumin, was negligible until 30 minutes after injection when small amounts appeared in the kidneys and bone marrow. Only 24% of the 125I-labeled, desialylated recombinant erythropoietin was recovered immediately after injection, and 96% of the hormone was cleared from the plasma with a t1/2 of 2.0 minutes. The bulk of the desialylated hormone accumulated in the liver where it was rapidly catabolized and its breakdown products released back into the plasma. Significantly, in contrast to unmodified erythropoietin, there was also early accumulation of desialylated hormone in the kidneys, marrow, and spleen. Desialylated orosomucoid but not orosomucoid, yeast mannan, or dextran sulfate 500 inhibited the rapid plasma clearance and hepatic accumulation of desialylated erythropoietin. Oxidation of the desialylated hormone restored its plasma recovery and clearance to normal but rendered it biologically inactive, and accumulation in organs other than the kidney was negligible.

scholarly journals The in vivo metabolism of recombinant human erythropoietin in the rat

Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 90-99 ◽  
Author(s):  
JL Spivak ◽  
BB Hogans
Keyword(s):  
Recombinant Human Erythropoietin ◽  
Plasma Clearance ◽  
Dextran Sulfate ◽  
Volume Of Distribution ◽  
Human Albumin ◽  
Recombinant Erythropoietin ◽  
Elimination Phase ◽  
Human Erythropoietin ◽  
Distribution Phase

Abstract We compared the in vivo plasma clearance and organ accumulation in anesthetized rats of 125I-labeled, recombinant human erythropoietin and 125I-labeled, desialylated recombinant erythropoietin. The immediate volume of distribution of 125I-labeled, recombinant erythropoietin approximated that of the plasma volume. Its plasma clearance was multiexponential, with an initial rapid distribution phase (t1/2 = 53 minutes) and a slower elimination phase (t1/2 = 180 minutes). Organ accumulation of labeled recombinant erythropoietin, as compared with 125I-labeled human albumin, was negligible until 30 minutes after injection when small amounts appeared in the kidneys and bone marrow. Only 24% of the 125I-labeled, desialylated recombinant erythropoietin was recovered immediately after injection, and 96% of the hormone was cleared from the plasma with a t1/2 of 2.0 minutes. The bulk of the desialylated hormone accumulated in the liver where it was rapidly catabolized and its breakdown products released back into the plasma. Significantly, in contrast to unmodified erythropoietin, there was also early accumulation of desialylated hormone in the kidneys, marrow, and spleen. Desialylated orosomucoid but not orosomucoid, yeast mannan, or dextran sulfate 500 inhibited the rapid plasma clearance and hepatic accumulation of desialylated erythropoietin. Oxidation of the desialylated hormone restored its plasma recovery and clearance to normal but rendered it biologically inactive, and accumulation in organs other than the kidney was negligible.

scholarly journals Survival of recombinant erythropoietin in the circulation: the role of carbohydrates

Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 84-89
Author(s):  
MN Fukuda ◽  
H Sasaki ◽  
L Lopez ◽  
M Fukuda
Keyword(s):  
Recombinant Human Erythropoietin ◽  
Binding Protein ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Recombinant Erythropoietin ◽  
Lectin Affinity Chromatography ◽  
Glycoprotein Hormone ◽  
Human Erythropoietin

Recombinant human erythropoietin produced in transfected Chinese hamster ovary cells is glycosylated much the same way as the erythropoietin present in human urine. To determine the role of carbohydrates in the stability of recombinant human erythropoietin in vivo, [125I]-labeled recombinant erythropoietin was intravenously infused into rats. The erythropoietin was slowly cleared from the blood with a half-life of approximately two hours. Asialoerythropoietin, which was produced by treatment of recombinant human erythropoietin with sialidase, was found to be cleared rapidly from circulation within ten minutes. These data suggest that the galactose binding protein of hepatic cells is involved in the clearance of asialoerythropoietin. Erythropoietin also contains N-glycans with a few N-acetyllactosamine repeats, which can be enriched by tomato lectin affinity chromatography. The lectin-bound fraction was cleared to a larger extent than was the unfractionated erythropoietin, while the component that did not bind the lectin was found to be stable in the circulation. Authentic N-acetyllactosamine repeats (polylactosaminoglycans) prepared from erythrocytes were similarly rapidly cleared from the circulation to the liver, and this clearance was inhibitable with asialo-alpha 1- acid glycoprotein. These results suggest that (a) the sialic acid of the recombinant erythropoietin is necessary for this glycoprotein hormone to circulate stably and (b) glycoproteins with more than three lactosaminyl repeat units may be cleared by the galactose binding protein of hepatocytes.

scholarly journals Survival of recombinant erythropoietin in the circulation: the role of carbohydrates

Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 84-89 ◽  
Author(s):  
MN Fukuda ◽  
H Sasaki ◽  
L Lopez ◽  
M Fukuda
Keyword(s):  
Recombinant Human Erythropoietin ◽  
Binding Protein ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Recombinant Erythropoietin ◽  
Lectin Affinity Chromatography ◽  
Glycoprotein Hormone ◽  
Human Erythropoietin

Abstract Recombinant human erythropoietin produced in transfected Chinese hamster ovary cells is glycosylated much the same way as the erythropoietin present in human urine. To determine the role of carbohydrates in the stability of recombinant human erythropoietin in vivo, [125I]-labeled recombinant erythropoietin was intravenously infused into rats. The erythropoietin was slowly cleared from the blood with a half-life of approximately two hours. Asialoerythropoietin, which was produced by treatment of recombinant human erythropoietin with sialidase, was found to be cleared rapidly from circulation within ten minutes. These data suggest that the galactose binding protein of hepatic cells is involved in the clearance of asialoerythropoietin. Erythropoietin also contains N-glycans with a few N-acetyllactosamine repeats, which can be enriched by tomato lectin affinity chromatography. The lectin-bound fraction was cleared to a larger extent than was the unfractionated erythropoietin, while the component that did not bind the lectin was found to be stable in the circulation. Authentic N-acetyllactosamine repeats (polylactosaminoglycans) prepared from erythrocytes were similarly rapidly cleared from the circulation to the liver, and this clearance was inhibitable with asialo-alpha 1- acid glycoprotein. These results suggest that (a) the sialic acid of the recombinant erythropoietin is necessary for this glycoprotein hormone to circulate stably and (b) glycoproteins with more than three lactosaminyl repeat units may be cleared by the galactose binding protein of hepatocytes.

scholarly journals Effect of Zinc Supplementation on Renal Anemia in 5/6-Nephrectomized Rats and a Comparison with Treatment with Recombinant Human Erythropoietin

2019 ◽  
Vol 20 (20) ◽  
pp. 4985 ◽  
Author(s):  
Hui-Lin Feng ◽  
Yen-Hua Chen ◽  
Sen-Shyong Jeng
Keyword(s):  
Bone Marrow ◽  
Recombinant Human Erythropoietin ◽  
Zinc Supplementation ◽  
Bone Marrow Cells ◽  
Human Erythropoietin ◽  
Post Surgery ◽  
Rat Bone ◽  
Marrow Cells

Anemia is a severe complication in patients with chronic kidney disease (CKD). Treatment with exogenous erythropoietin (EPO) can correct anemia in many with CKD. We produced 5/6-nephrectomized rats that became uremic and anemic at 25 days post surgery. Injection of the anemic 5/6-nephrectomized rats with 2.8 mg zinc/kg body weight raised their red blood cell (RBC) levels from approximately 85% of the control to 95% in one day and continued for 4 days. We compared the effect of ZnSO4 and recombinant human erythropoietin (rHuEPO) injections on relieving anemia in 5/6-nephrectomized rats. After three consecutive injections, both the ZnSO4 and rHuEPO groups had significantly higher RBC levels (98 ± 6% and 102 ± 6% of the control) than the saline group (90 ± 3% of the control). In vivo, zinc relieved anemia in 5/6-nephrectomized rats similar to rHuEPO. In vitro, we cultured rat bone marrow cells supplemented with ZnCl2, rHuEPO, or saline. In a 4-day suspension culture, we found that zinc induced erythropoiesis similar to rHuEPO. When rat bone marrow cells were supplement-cultured with zinc, we found that zinc stimulated the production of EPO in the culture medium and that the level of EPO produced was dependent on the concentration of zinc supplemented. The production of EPO via zinc supplementation was involved in the process of erythropoiesis.

scholarly journals N- and O-glycosylation muteins of recombinant human erythropoietin secreted from BHK-21 cells

Blood ◽  
1995 ◽  
Vol 85 (5) ◽  
pp. 1229-1236 ◽  
Author(s):  
MR Fibi ◽  
P Hermentin ◽  
JU Pauly ◽  
L Lauffer ◽  
G Zettlmeissl
Keyword(s):  
Transient Expression ◽  
Cell Lines ◽  
Recombinant Human Erythropoietin ◽  
Biologically Active ◽  
Wild Type ◽  
Expression Levels ◽  
Human Erythropoietin ◽  
Culture Supernatants ◽  
Secretion Rates

Single-site glycomuteins of recombinant human erythropoietin (rhuEpo) were constructed and transiently and stably expressed in BHK-21 cells. The transient expression levels varied among muteins, being highest for mutein rhuEpoGln24 followed by wild-type rhuEpo (rhuEpowt). All other glycomuteins, including rhuEpoGln38, rhuEpoGln83, rhuEpoThr126, and rhuEpoGly126, were secreted at lower levels than rhuEpowt. Muteins expressed in stable cell lines showed similar differences in expression levels. Also each mutein could be affinity-purified from culture supernatants, and was biologically active in vivo. Based on secretion rates from BHK-21 cells, the most potent erythropoietin was rhuEpoGln24. This mutein is also considered to have biologic activities that are superior to rhuEpowt.

scholarly journals Pharmacokinetics of sodium meclofenamate in pre-ruminant cattle

2004 ◽  
Vol 56 (6) ◽  
pp. 695-700
Author(s):  
E.J. Picco ◽  
D.C. Diaz David ◽  
T. Encinas ◽  
M.R. Rubio ◽  
J.C. Boggio
Keyword(s):  
High Performance ◽  
Pharmacokinetic Profile ◽  
Apparent Volume ◽  
Antiinflammatory Drug ◽  
Volume Of Distribution ◽  
Intramuscular Administration ◽  
Flip Flop ◽  
Elimination Phase ◽  
Distribution Phase ◽  
Apparent Volume Of Distribution

The pharmacokinetic profile of sodium meclofenamate, a non-steroidal antiinflammatory drug, was determined in six pre-ruminant calves after intravenous and intramuscular administration at a dose of 2.2mg/kg of body weight. Meclofenamate concentrations were measured using a high performance liquid chromatography assay. The pharmacokinetics of sodium meclofenamate after intravenous and intramuscular administration to calves were characterised by a rapid distribution phase (t½alpha ), 15.45± 4.85min and 23.14± 7.24min for the intravenous and intramuscular administration, respectively, followed by a longer elimination phase (t½beta ) after intramuscular treatment (17.55± 6.52h.). The apparent volume of distribution (Vd) of the drug after intravenous administration was moderate (0.72± 0.12l/kg), and high (3.51± 1.05l/kg) after intramuscular administration. This can be explained by the flip-flop effect or by enterohepatic shunting. The bioavailability achieved after intramuscular administration was 61%.

scholarly journals Recombinant human erythropoietin separation using a cation-exchange multimodal adsorbent

2019 ◽  
Vol 12 (1) ◽  
pp. 103-107
Author(s):  
Marta Ostrihoňová ◽  
Jana Adamíková ◽  
Tomáš Molnár ◽  
Monika Antošová ◽  
Milan Polakovič
Keyword(s):  
Cation Exchange ◽  
Chromatographic Separation ◽  
Recombinant Human Erythropoietin ◽  
Batch Adsorption ◽  
Recombinant Erythropoietin ◽  
Optimal Conditions ◽  
Effect Of Ph ◽  
Human Recombinant Erythropoietin ◽  
Human Erythropoietin ◽  
Nacl Concentration

Abstract This work deals with the capture of human recombinant erythropoietin (rhEPO) from a mixture of proteins in a concentrated postcultivation supernatant. Cation-exchange multimodal adsorbent Capto MMC ImpRes was selected as potential chromatographic separation material. Its equilibrium properties were investigated in batch adsorption experiments. The effect of pH in the range of 5.5—7.5 and NaCl concentration in the range of 0—300 mM on the adsorption of rhEPO and contaminant proteins was examined. Optimal conditions found in these equilibrium experiments were applied to rhEPO adsorption in a chromatographic column. Several experiments were carried out at different elution conditions to optimize the rhEPO yield and selectivity.

Haemostatic Effects of Recombinant Human Erythropoietin in Chronic Haemodialysis Patients

1989 ◽  
Vol 61 (01) ◽  
pp. 117-121 ◽  
Author(s):  
Chris van Geet ◽  
Didier Hauglustaine ◽  
Luc Verresen ◽  
Marleen Vanrusselt ◽  
Jos Vermylen
Keyword(s):  
Platelet Count ◽  
Recombinant Human Erythropoietin ◽  
Bleeding Time ◽  
Chronic Haemodialysis ◽  
Recombinant Erythropoietin ◽  
The Third ◽  
Human Erythropoietin ◽  
Platelet Number ◽  
Almost All ◽  
And Function

SummaryRecombinant human erythropoietin was administered for up to 40 weeks to nine patients on chronic haemodialysis. From the third week of administration onwards, not only haemoglobin and haematocrit but also the platelet count rose, the latter, however, transiently. Subnormal platelet aggregation before therapy also improved transiently and in parallel with the erythropoietin dosage. The bleeding time normalized in almost all patients. There were no major side-effects. We conclude that recombinant erythropoietin improves haemostasis in chronic haemodialysis patients by increasing the haematocrit and in addition transiently enhances platelet number and function.

Sign in / Sign up

Export Citation Format

Share Document