Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Renal anemia is the result of reduced erythropoietin (EPO) biosynthesis in the diseased kidney and also in part the result of a reduced life span of red blood cells (RBCs). An increase in density and a decrease in enzyme equipment (aspartate aminotransferase; GOT) of RBCs reflect cell age. In the following study, the density distribution (median density D50; determined by Percoll density gradients) and GOT activities of RBCs were measured in patients on acetate (HDA; n = 15) and bicarbonate (HDB; n = 51) hemodialysis. Hemoglobin (Hb) concentrations were: in the HDB group, 9.1 +/- 3.4 g/dl; in the HDA group, 6.2 +/- 1.2 g/dl, and, in a control (C) group of healthy persons, 14.0 +/- 1.5 g/dl. 14 HDB patients with severe anemia received EPO therapy during 1 year. D50 were found as follows: group C, 1.0674 +/- 0.0016 g/ml; HDB, 1.0674 +/- 0.0015 g/ml, and HDA, 1.0660 +/- 0.0012 g/ml (HDA vs. group C: p less than 0.05; HDA vs. HDB: p less than 0.05. D50 were elevated in the subgroups of HDA and HDB patients with severe anemia (Hb less than 8 g/dl). During activated erythropoiesis by EPO therapy, D50 decreased from 1.06739 +/- 0.0015 to 1.0656 +/- 0.0014 g/ml. The GOT activities in RBCs demonstrated a rejuvenation of the RBC population in the HDB group (6.4 +/- 2.5 U/g Hb) and HDA group (5.9 +/- 3.1 U/g Hb) compared to group C (3.9 +/- 1.3 U/g Hb).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Red blood cell density distribution in uremic patients on acetate and bicarbonate hemodialysis. 196 10

Renal anemia is caused in part by a reduced life span of red blood cells (RBCs) and by reduced erythropoietin biosynthesis in the damaged kidney. The RBC age can be determined by density gradient centrifugation and estimation of cell-age-dependent enzyme activities, as aspartate aminotransferase. The RBC age distribution influences the median density (D50) of RBCs and the blood rheology in coherence with the hematocrit. In our study, the median density was determined by Percoll density gradient centrifugation in 18 healthy subjects (D50 = 1.0674 +/- 0.0016 g/ml) and in 14 hemodialysis patients (D50 = 1.0674 +/- 0.0016 g/ml in the course of recombinant human erythropoietin (rhEPO) therapy. During the first 4 weeks of therapy, a strong rejuvenation of RBCs was observed whereby the D50 reached a minimum after 2 weeks (D50 = 1.0655 +/- 0.0022 g/ml; p less than 0.05 vs. value before therapy) and a steady state after 4 weeks (D50 = 1.0658 +/- 0.0013 g/ml; p less than 0.1 vs. value before therapy). In 5 of the patients with elevated plasma parathyroid hormone (i-PTH) concentrations greater than 10 pmol/l, a significantly (p less than 0.05) reduced amount of younger RBCs (D50 = 1.0675 +/- 0.0016 g/ml) was observed in the first 2 weeks of rhEPO therapy as compared to patients with i-PTH less than 10 pmol/l (D50 = 1.0677 +/- 0.0019 g/ml). Thus, erythropoiesis in the early phase of rhEPO therapy is strongly influenced by elevated plasma i-PTH concentrations. Therefore, a gradual increase in rhEPO doses is preferable before therapy at elevated doses with an uncontrolled increase in RBC amount.
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PMID:Erythropoiesis and erythrocyte age distribution in hemodialysis patients undergoing erythropoietin therapy. 224 89