Effect of human erythropoietin (hEPO) treatment on anemia in ICR-derived glomerulonephritis (ICGN) mice.

ICR-derived glomerulonephritis (ICGN) mice are a novel inbred strain with hereditary nephrotic syndrome and are thus considered a good animal model of human idiopathic nephrotic syndrome. In the present study, we investigated the effect to erythrocyte production by human erythropoietin (hEPO) treatment in ICGN mice during the early nephrotic stage. Erythrocyte count, hemoglobin concentration and hematocrit value in hEPO-treated (5 U/body/day, for 5 days) ICGN mice were recovered to the levels found in normal ICR mice. In addition, there was no correlation between plasma creatinine level, a marker of renal function, and erythrocyte count after hEPO treatment. Therefore, anemia in ICGN mice may be caused by decreased production of EPO in the kidney following progressive parenchymal damage.     

Pharmacokinetics and Pharmacodynamics of Recombinant Human EPO-Fc Fusion Protein In Vivo

In this study, the in vivo pharmacokinetics and pharmacodynamics of a novel recombinant human erythropoietin (rhEPO) Fc fusion protein, rhEPO-Fc, were studied in both rodents and rhesus monkeys. Animal models of anemia induced by irradiation, cyclophosphamide and partial renal ablation were used to evaluate therapeutic effects of rhEPO-Fc. We have demonstrated that serum half-life of rhEPO-Fc was 29.5 to 38.9 h at doses of 8, 25, 80 µg/kg in rhesus monkeys and 35.5 to 43.5 h at doses of 16, 50, 160 µg/kg in rats. In anemia animal models, rhEPO-Fc dose-dependently (7.5–30.0 µg/kg in mice, 5.4–21.4 µg/kg in rats and 5.0–10.0 µg/kg in rhesus monkeys) increased reticulocyte level, followed by an increase of RBC count, hemoglobin and hematocrit levels. At reduced intervention frequency of weekly treatments, rhEPO-Fc showed similar hematopoietic effects as compared with rhEPO given three times a week. These results indicated that rhEPO-Fc could potentially be used in treatment of anemia and warrants future clinical trials.     

Effect of recombinant human erythropoietin on the anemia of chronic renal failure

Phase I and Phase II studies of recombinant human erythropoietin (rhEpo) were conducted in normal volunteers and in anemic patients with chronic renal failure on maintenance hemodialysis. Three hundred U/person of rhEpo was administered intravenously to healthy normal volunteers in the Phase I study, resulting in no subjective or objective changes. In the Phase II study, 66 patients with chronic renal failure on maintenance hemodialysis with less than 20% hematocrit values were treated with rhEpo in doses of 50 U/kg to 200 U/kg two or three times a week. Hematocrit values increased significantly during the 12 weeks, and the patients' conditions improved. Patients previously requiring blood transfusions became transfusion-independent during our study. There were no obvious side effects, thus indicating the safety and efficacy of rhEpo in the anemia of chronic renal failure.     

Disturbances of morphological parameters in blood of rats orally exposed to aluminum chloride

The aim of this work was to assess changes of morphological parameters in the blood of rats after oral (po) administration of aluminum (Al), in relation to the time and the administered dose. The experiment was performed on female Wistar rats. The animals were administered aluminum chloride (100 mg Al/kg) daily for 21 d. Morphological assays: red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), iron serum concentration (Fe), MCH, MCHC, absolute corrected reticulocyte count (ACRC), white blood cells (WBC), and platelet count (PLT) were estimated on d 3, 7, 14, and 21, both in the control group and in intoxicated rats. After wk 1 of aluminum administration we observed a decrease of RBC, HCT, HGB and serum iron concentration in the blood of rats. The increase of the platelet count was observed earlier than changes in other parameters. Investigation has proved that the exposure of rats to aluminum administered orally results in normocytic anemia.     

Effects of L-carnosine on blood cells and biomembrane

The white blood cell count in the peripheral blood decreased to 57% of the control in ddY mice after intraperitoneal administration of 3-azido-3-deoxythymidine (AZT, 500 mg/kg/day), mitomycin C (MMC, 1 mg/kg/day), or 5-fluorouracil (5-FU, 50 mg/kg/day) for 7 days or general gamma-irradiation at 35 rad. However, this reduction was significantly prevented by administering L-carnosine (CAR) or beta-alanine (beta-ALA) simultaneously or subcutaneously for 7 days from the day after irradiation, suggesting an anti-leukopenic effect of CAR. When Wistar rats were administered phenylhydrazine (PHZ, 40 mg/kg) twice 1 and 3 days before evaluation, the red blood cell count was reduced to 55% of the control. However, the reduction was to 69% in the group treated with CAR for 8 days from 9 days prior to evaluation. The hematocrit and hemoglobin level were also increased by the administration of CAR, suggesting a protective effect of the agent against hemolytic anemia. Since membrane stabilization is considered to be the mechanism of this effect lysosome-rich fraction isolated from the liver of Wistar rats were incubated in 0.2 M sucrose with CAR, and the acid phosphatase activity released into the incubation medium was measured. CAR was found to have a membrane-stabilizing effect, which reached a plateau at a final concentration of 2.5 mM. This membrane stabilizing effect was not observed with beta-ALA or L-histidine (HIS) alone at a final concentration of 5 mM, and the release of the enzyme was only slightly inhibited by HIS + beta-ALA. Therefore, CAR molecules are considered to be needed for membrane stabilization.     

Gene therapy for rat renal anemia with implantation of erythropoietin-transgenic myoblasts

To investigate whether an erythropoietin (EPO) gene-based therapy could serve as an alternative to the repeated injection of rhEPO in treatment to renal anemia, the genetically modified myoblasts of rats, named Myo/ EPO, were implanted through intramuscular injection to model rats with renal anemia. The hemoglobin (Hb) and hematocrit (HCT) of the rats increased from (92.5 ±3.0) g/L and 0.29±0.04 to the peak values of (103.8 ±5.0) g/L and 0. 32 ±0. 04 respectively 14 d after implantation, and sustained the pre-implantation level for 90 d. Otherwise, the control rats implanted with Myo/X, which carried the parent retroviral vector, gradually became severe in anemia. The PCR detection for hEPO cDNA in the rat muscle adjacent to injection sites indicated that the Myo/EPO cells survived for a long period in the muscle of rats. The results primarily demonstrate that myoblast gene transfer of EPO is effective for the treatment of rat renal anemia.     

Gene therapy for rat renal anemia with implantation of erythropoietin-transgenic myoblasts

To investigate whether an erythropoietin (EPO) gene-based therapy could serve as an alternative to the repeated injection of rhEPO in treatment to renal anemia, the genetically modified myoblasts of rats, named Myo/ EPO, were implanted through intramuscular injection to model rats with renal anemia. The hemoglobin (Hb) and hematocrit (HCT) of the rats increased from (92. 5±3.0) g/L and 0.29 ±0.04 to the peak values of (103.8 ±5.0) g/L and 0. 32 ±0. 04 respectively 14 d after implantation, and sustained the pre-implantation level for 90 d. Otherwise, the control rats implanted with Myo/X, which carried the parent retroviral vector, gradually became severe in anemia. The PCR detection for hEPO cDNA in the rat muscle adjacent to injection sites indicated that the Myo/EPO cells survived for a long period in the muscle of rats. The results primarily demonstrate that myoblast gene transfer of EPO is effective for the treatment of rat renal anemia.     

Blood viscosity parameter correlation with types of leukemia.

We investigated the hemorheological, hematological and biochemical parameters in 30 cases of acute lymphocytic leukemia (ALL), 21 cases of acute myelogenous leukemia (AML) and 30 cases of chronic myelogenous leukemia (CML). The parameters studied include whole blood viscosity, plasma viscosity, erythrocyte sedimentation rate (ESR), red cell filterability, hematocrit, platelet count and aggregation, fibrinogen, hemoglobin, leucocyte count, bleeding time and lactate dehydrogenase activity (LDH). In the cases of ALL we observed significant decrease in whole blood viscosity, hemoglobin, hematocrit and platelet count but an increase in plasma viscosity, fibrinogen, bleeding time and LDH activity. In the cases of AML, we observed increase in whole blood viscosity, plasma viscosity, ESR, fibrinogen, leucocyte count, bleeding time and LDH activity but decrease in the hemoglobin, hematocrit and platelet count. In the cases of CML, we observed an increase of whole blood viscosity, plasma viscosity, ESR, fibrinogen elevation but decreases in bleeding time. In all cases, red cell filterability was unaffected.     

The effect of atrial natriuretic peptide on acid-base balance in rats with chronic renal failure

We explored the effects of 12-hour infusion of atrial natriuretic peptide (alpha-rANP:rat, 1-28) on arterial acid-base balance, using 5/6 nephrectomized rats with chronic renal failure. Before the infusion, nephrectomized rats had a higher mean arterial blood pressure, greater urine volume, and lower creatinine clearance than the normal controls, but they did not show a significant difference in arterial hydrogen ion concentration (pH), plasma bicarbonate concentration (HCO3-), partial pressure of carbon dioxide (PCO2), plasma base excess (BE), or plasma ANP concentration. alpha-rANP infusion produced a continuous blood pressure reduction in both nephrectomized and control rats. Urine volume and urinary sodium and potassium excretion tended to increase at 2-hour infusion, but not at 12-hour infusion. In the controls alpha-rANP significantly increased pH from 7.47 to 7.50, and decreased PCO2 by 14%. In contrast, in nephrectomized rats alpha-rANP significantly decreased pH from 7.48 to 7.44, HCO3- by 13%, and BE from -0.07 to -3.22 meq/l. Rats with chronic renal failure had greater reduction in HCO3- than the controls (p less than 0.05). There was no difference in plasma ANP level between the two groups. Thus, it is indicated that the long-term infusion of alpha-rANP reduces pH in rats with chronic renal failure, thereby adversely affecting the acid-base balance.     

Increased arterial potassium transport in reduced renal mass hypertension of the rat

Aortic potassium turnover was studied during the development of hypertension induced by salt load in male rats after 70-75% of total renal mass was removed. Systolic blood pressure in the saline-drinking experimental reduced renal mass (RRM) rats steadily increased until the fourth week after surgery and thereafter stayed at the same level. Control RRM rats given tap water for drinking, and unilaterally nephrectomized saline-drinking control rats maintained normal blood pressure. Compared to controls, experimental RRM rats exhibited increased plasma aldosterone concentration while plasma renin activity was low in all groups with no significant difference. Aortic hypertrophy, greater 42K turnover, and elevated 42K exchange were observed with experimental RRM hypertension. Sensitivity to the effect of norepinephrine (NE) on aortic 42K turnover was increased four- to ninefold in the experimental RRM group as compared to controls. These results indicate that reduced renal mass hypertension is associated with increased potassium permeability and NE supersensitivity in vascular smooth muscle.     

Effectiveness of Green Tea Tannin on Rats with Chronic Renal Failure

The effects of green tea tannin on nephrectomized rats were examined. There were increases in blood urea nitrogen, serum creatinine, and urinary protein, and a decrease in creatinine clearance in the nephrectomized control rats, whereas better results for these parameters were obtained in rats given green tea tannin after nephrectomy, demonstrating a suppressed progression of the renal failure. When the renal parenchyma was partially resected, the remnant kidney showed a decrease in the activity of radical scavenger enzymes. Green tea tannin, however, was found to lighten the kidney under such oxidative stress. Mesangial proliferation and glomerular sclerotic lesions, which were conspicuous in the rats that were not given green tea tannin after nephrectomy, were also relieved.     

Single dose recombinant human erythropoietin reduces transforming growth factor beta in patients on chronic haemodialysis.

Short-term effects of recombinant human erythropoietin on serum levels of transforming growth factor beta-1, interleukin 1-alpha, interleukin 3, interferon gamma, and tumour necrosis factor alpha in patients with chronic renal failure on chronic haemodialysis were investigated. Recombinant human erythropoietin was applied subcutaneously in a dose of 75 IU/kg on 19 patients. Serum levels of transforming growth factor beta-1, interleukin 1-alpha, interleukin 3, interferon gamma, tumour necrosis factor alpha and erythropoietin, red blood cell parameters: red blood cell count, haemoglobin, haematocrit, and erythrocyte indices were determined before and after recombinant human erythropoietin single application. Transforming growth factor beta-1 serum levels were decreased after recombinant human erythropoietin (22.70 +/- 1.51 ng/ml versus 18.77 +/- 1.70 ng/ml (p < 0.01). None of the other investigated parameters was influenced significantly by recombinant human erythropoietin. Recombinant human erythropoietin in patients with chronic renal failure on chronic haemodialysis may influence anaemia not only through its stimulating effect on erythropoiesis, but also by direct oxygen-independent decrease of at least one of the negative regulators of erythropoiesis--the transforming growth factor beta.     

Angiotensin II generation in mesenteric arteries in rats: effects of nephrectomy, deoxycorticosterone and dexamethasone

Angiotensin II (ANG II) generation in the mesenteric arteries was studied in four groups of rats: deoxycorticosterone (DOCA)/salt treated, glucocorticoid treated, nephrectomized and control rats. Basal plasma renin activity (PRA) was undetectable in the nephrectomized group and suppressed in the DOCA/salt treated rats, but was increased in the rats treated with glucocorticoid. The Basal plasma ANG II concentration changed comparably with PRA in all four groups of rats. In the control rats, ANG II was released from the mesenteric arteries at a rate of 43.0 +/- 12.0 pg/h, and it was not decreased by nephrectomy. In DOCA/salt rats and glucocorticoid rats, ANG II release significantly decreased to 12.8 +/- 7.1 and 6.9 +/- 1.5 pg/h, respectively. Captopril treatment significantly reduced ANG II release from the mesenteric arteries in both controls and nephrectomized rats, but did not influence ANG II output in DOCA/salt rats or in glucocorticoid treated rats. In nephrectomized rats, captopril lowered blood pressure in association with a significant reduction in the mesenteric ANG II formation. These results indicate that the renal and vascular renin-angiotensin system (RAS) may be independently regulated, and in nephrectomized animals the vascular RAS contributes in part to the maintenance of blood pressure. The present results also suggest that volume expansion per se and/or pharmacological intervention by DOCA and glucocorticoid could modulate vascular ANG II generation.     

Tobacco smoking causes secondary polycythemia and a mild leukocytosis among heavy smokers in Taif City in Saudi Arabia

Tobacco smoking is a common risk factor of cardiovascular diseases, cancers and heart health problems. In Taif, the number of secondary polycythemia patients is increasing dramatically and most of those patients are heavy smokers. Therefore, this study is an attempt to understand the pathophysiological mechanism behind that problem. Whole blood and serum samples were collected from forty healthy people and forty tobacco smokers, voluntary for this study. Complete blood counts revealed a significant increase in the red blood cell count, hemoglobin concentrations, hematocrit and neutrophils with some elevations in total white blood cells, lymphocytes and monocytes. Moreover, serum analysis of both erythropoietin and interleukin-7 showed a significant reduction in their levels among smokers which were about 35% and 65% respectively. Gene expression study showed a significant upregulation of RAG-1, RAG-2 and EPOR-1 genes caused by tobacco smoking. In conclusion, data presented in the current study suggest that tobacco smoking might cause alveolar tissue inflammation and vascular injury causing an immune response that elevates the white blood cells count. Another suggestion is that tobacco smoking defects the pulmonary gaseous exchange mechanism leading to the secondary polycythemia indicated by the increase in red blood cell count, hemoglobin levels, hematocrit and by the low serum erythropoietin levels.     

Phostoxin-induced biochemical and pathomorphological changes in rabbits

The effect of chronic phostoxin administration on some tissue ATPases, hematology and tissue histopathology was investigated using a combination of gravimetric, enzymatic, colorimetric and histological procedures in New Zealand White rabbits after 2 weeks administration of 0.8mg phostoxin/kg body weight/day, po. The phostoxin treatment led to significant decreases in Na(+)-K+ ATPase activities in renal, hepatic and cardiac tissues. Similar decreases were obtained in the activities of Ca(2+)-ATPase and Mg(2+)-ATPase in liver. In addition, the phostoxin-toxified rabbits manifested significant decreases in hematocrit, red blood cell count, hemoglobin and platelets. Histological examination of the tissues revealed pronounced degenerative changes in liver, heart and kidney.     

High intakes of tin lower iron status in rats

The effects of relatively low (1, 10, and 50 mg/kg) and high (100 and 200 mg/kg) dietary concentrations of tin (added as stannous chloride) on iron status of rats were determined. After feeding the diets for 28 d, feed intake and body weights were not significantly affected. Iron concentrations in plasma, spleen, and tibia as well as percentage transferrin saturation were decreased in rats fed the diets supplemented with 100 or 200 mg tin/kg. In rats fed the diet containing 200 mg tin/kg, group mean hemoglobin, hematocrit, and red blood cell count were slightly lowered but total iron binding capacity was not affected. Iron status was not influenced by dietary tin concentrations lower than 100 mg/kg. If these results can be extrapolated to humans, then it may be concluded that tin concentrations in the human diet, which range from 2 to 76 mg/kg dry diet, do not influence iron status in humans.     

The activity of erythrocyte enzymes in rats subjected to running exercises

The studies were carried out on male Wistar rats subjected to running within an electric rotating drum. The animals were divided into four experimental groups, differing one from another as to the duration of training. Each training session lasted 30 days. In the first group the daily run lasted 3 min, in the second group 5 min; in the third group, a 1 min run on the first day, and one min longer on each successive day; in the fourth group a 2 min run on the first day and for two min longer on each successive day. The determinations made prior to and after training included the peripheral blood erythrocyte (Er) and reticulocyte (Ret.) count, the hemoglobin concentration (Hb) and packed cell volume (PCV) and, determined by spectrophotometric methods, the activity of pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD) and glutathione reductase (GR). Training induced an improvement of all enzymatic activities. The heavier the physical exertion, the more intensive was the enzymatic activity of red blood cells, due to the intensification of bone marrow erythropoetic activity under physical exertion and the appearance of young red cells in peripheral blood. All the experimental groups revealed a drop in erythrocyte count (Er), hemoglobin concentration (Hb), and hematocrit values (PCV), as well as an increase in the reticulocytes count (Ret) and in the activity of all the enzymes investigated. In the fourth group anemia was detected: prolonged endurance training decreased the RBC by 24.2%, Hb by 31.1%, PCV by 26.2% and increased the reticulocyte count by 881.6%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased expression of (pro)renin receptor in the remnant kidneys of 5/6 nephrectomized rats

Recent studies have revealed that (pro)renin receptor ((P)RR), a newly identified member of the renin–angiotensin system, is associated with renal organ damage. However, there is little information regarding the regulation of (P)RR expression in various pathophysiological conditions. We therefore examined the expression of (P)RR in the remnant kidneys of rats with renal mass ablation due to 5/6 nephrectomy by quantitative RT-PCR, Western blot analysis and immunohistochemistry. Expression levels of (P)RR mRNA were significantly increased in the remnant kidneys at day 56 after nephrectomy, when compared with sham operation (about 1.6-fold, P = 0.001). Western blot analysis showed that expression levels of (P)RR protein were greatly increased in the remnant kidneys at day 56, compared with sham operation (about 7.9-fold, P = 0.02). The renal tubular cells were immunostained with anti-(P)RR antibody in both 5/6 nephrectomized rats and sham operated rats. The glomeruli were sporadically immunostained in 5/6 nephrectomized rats, but not in sham operated rats. These findings indicate that the intra-renal (P)RR expression is increased in the remnant kidneys of 5/6 nephrectomized rats, and suggest that (P)RR may contribute to the renal injury.