losartan-potassium and Necrosis

Following stroke or traumatic damage, neuronal death via both necrosis and apoptosis causes loss of functions, including memory, sensory perception, and motor skills. As necrosis has the nature to expand, while apoptosis stops the cell death cascade in the brain, necrosis is considered to be a promising target for rapid treatment for stroke. We identified the nuclear protein, prothymosin alpha (ProTalpha) from the conditioned medium of serum-free culture of cortical neurons as a key protein-inhibiting necrosis. In the culture of cortical neurons in the serum-free condition without any supplements, ProTalpha inhibited the necrosis, but caused apoptosis. In the ischemic brain or retina, ProTalpha showed a potent inhibition of both necrosis and apoptosis. By use of anti-brain-derived neurotrophic factor or anti-erythropoietin IgG, we found that ProTalpha inhibits necrosis, but causes apoptosis, which is in turn inhibited by ProTalpha-induced neurotrophins under the condition of ischemia. From the experiment using anti-ProTalpha IgG or antisense oligonucleotide for ProTalpha, it was revealed that ProTalpha has a pathophysiological role in protecting neurons in stroke.

Topics: Apoptosis; Brain; Brain-Derived Neurotrophic Factor; Cell Death; Cerebral Cortex; Culture Media, Conditioned; Erythropoietin; Immunoproteins; Ischemia; Necrosis; Nerve Growth Factors; Neurons; Protein Precursors; Retina; Stroke; Thymosin

The kidney has the ability to restore the structural and functional integrity of the proximal tubule, which undergoes extensive epithelial cell death via necrosis and apoptosis after a prolonged ischaemic insult. This review focuses on the recent advances in this area, and discusses the possible therapeutic interventions that might be derived from these insights.. Interest has recently been focused on the possible role of bone marrow originating stem cells in endogenous repair of the injured tubule, the identification of a resident population of progenitor cells in the kidney, and the potential therapeutic role of growth factors including erythropoietin and hepatocyte growth factor to stimulate these processes.. Advances in the understanding of the early processes that initiate and control the proliferation of surviving tubular epithelium and vascular structures are ready to be translated into clinical trials in acute kidney injury.

Topics: Acute Kidney Injury; Apoptosis; Epithelium; Erythropoietin; Humans; Intercellular Signaling Peptides and Proteins; Ischemia; Kidney; Kidney Tubules, Proximal; Mesoderm; Necrosis; Stem Cells

Erythropoietin (Epo) was once thought to act exclusively in the formation of red blood cells. As recently reviewed by Smith et al. [Cardiovasc. Res. 59 (2003) 538-548], Epo can also act within the cardiovascular system with effects in thrombosis and hypertension as well as actions on platelets, vascular endothelium and smooth muscle, and myocytes of the heart. Here, the actions of Epo to protect neuronal cells of the brain are first evaluated and parallel actions of Epo in cardioprotection are then drawn. Thus, with recent reports of Epo receptor (EpoR) expression by cardiac myocytes, it could be predicted that Epo initiates direct protective signalling events. This is supported by five independent studies published in 2003 showing Epo protects cardiac myocytes following ischemia/reperfusion. Importantly, these protective actions have been observed in vitro and in vivo. The former suggests the direct actions of Epo to prevent myocyte death independently of its effects on red blood cell number or cells other than cardiac myocytes. The latter demonstrates the potential for Epo in the treatment of the heart post-infarction, decreasing the numbers of apoptotic myocytes, limiting infarct expansion and attenuating the post-infarct deterioration in haemodynamic function. These beneficial effects of Epo should stimulate further research into the actions of Epo.

Topics: Animals; Apoptosis; Erythropoietin; Humans; Myocardial Reperfusion Injury; Myocardium; Myocytes, Cardiac; Necrosis; Neurons

To share our initial experience with the innovative use of topical erythropoietin for the treatment of necrotizing scleritis manifesting immediately after pterygium excision surgery.. This study enrolled 3 patients who developed necrotizing scleritis immediately after undergoing pterygium excision. All cases with pterygium were primary, and topical mitomycin C and conjunctival autografts were used at the time of surgery. Noninvasive therapy that included ophthalmic lubricants and topical and systemic corticosteroids failed to improve the avascular scleral lesions. The patients were prescribed erythropoietin-containing drops (3000 U/mL) every 6 hours in addition to topical antibiotics and lubricant. The effect of topical erythropoietin on the healing process of avascular scleral lesions was investigated, and its ocular and systemic side effects were evaluated.. The mean age of the participants was 69.0 ± 14.8 years, and 2 of the 3 eyes belonged to male subjects. The time between pterygium surgery and presentation to our clinic was 33.0 ± 14.7 days. There were no infectious causes or underlying systemic diseases in any of the cases. After treatment with topical erythropoietin for an average of 34.3 ± 20.3 days, the lesions were completely vascularized in all 3 eyes without any ocular or systemic adverse effects. The patients were followed up for an average of 126 ± 94 days after discontinuation of erythropoietin. There was no evidence of recurrence during the last examination in any of the eyes.. Topical erythropoietin might be a safe and an effective method for treating cases of necrotizing scleritis that manifests immediately after pterygium surgery.

Topics: Administration, Topical; Aged, 80 and over; Conjunctiva; Erythropoietin; Female; Follow-Up Studies; Humans; Male; Middle Aged; Necrosis; Ophthalmologic Surgical Procedures; Pilot Projects; Postoperative Complications; Pterygium; Retrospective Studies; Sclera; Scleritis; Treatment Outcome

It has been shown that pre- and postconditioning of ischemically challenged tissue with erythropoietin (EPO) is able to reduce necrosis in a dose-dependent manner. The aim of this study was to determine the tissue-protective effects of different EPO dosages and administration regimes. Three groups of six C57Bl/6-mice each were analyzed: (1) pre- and postconditioning with initial high doses of EPO (starting at 2500 I.U./kg bw i.p.) followed by low doses of EPO (125 I.U./kg bw i.p.) (EPO-high-dose); (2) pre- and postconditioning with low doses of EPO (125 I.U./kg bw i.p.) (EPO-low-dose); and (3) untreated control group. Randomly perfused musculocutaneous flaps were mounted on dorsal skinfold chambers undergoing acute persistent ischemia and developing ∼50% necrosis without treatment. Intravital epifluorescence microscopy was performed at days 1, 3, 5, 7, and 10 after surgery, assessing flap necrosis, microcirculation, and angiogenesis. The hematocrit was measured at days 0, 3, 7, and 10. Only the EPO-low-dose regimen was associated with a significant reduction of necrosis when compared to untreated controls. EPO-low-dose showed a higher increase in both arteriolar diameter and velocity, thereby resulting in a significantly increased arteriolar blood flow and a hence higher functional capillary density (FCD) of the critically perfused zone. EPO-induced angiogenesis was significantly increased in EPO-low-dose at days 7 and 10. Only EPO-high-dose reached a significant hematocrit increase by day 10. Tissue pre- and postconditioning with low doses of EPO protects the critically perfused musculocutaneous tissue by maintaining capillary perfusion because of increased arteriolar blood flow mediated by nitric oxide (NO) expression.

Topics: Animals; Erythropoietin; Mice; Mice, Inbred C57BL; Microcirculation; Microscopy, Fluorescence; Myocutaneous Flap; Necrosis; Perfusion

Inflammatory responses play critical roles in carbon monoxide (CO) poisoning-induced cerebral injury. The present study investigated whether erythropoietin (EPO) modulates the toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) inflammatory signaling pathways in brain injury after acute CO poisoning. EPO (2500 and 5000 U/kg) was injected subcutaneously twice a day after acute CO poisoning for 2 days. At 48 h after treatment, the expression levels of TLR4 and NF-κB as well as the levels of inflammatory cytokines in the hippocampal tissues were measured. Our results showed that CO poisoning induced a significant upregulation of TLR4, NF-κB, and inflammatory cytokines in the injured rat hippocampal tissues. Treatment with EPO remarkably suppressed the gene and protein expression levels of TLR4 and NF-κB, as well as the concentrations of TNF-α, IL-1β, and IL-6 in the hippocampal tissues. EPO treatment ameliorated CO poisoning-induced histological edema and neuronal necrosis. These results suggested that EPO protected against CO poisoning-induced brain damage by inhibiting the TLR4-NF-κB inflammatory signaling pathway.

Topics: Animals; Brain Injuries; Carbon Monoxide; Carbon Monoxide Poisoning; Edema; Erythropoietin; Hippocampus; Inflammation; Interleukin-1beta; Interleukin-6; Male; Maze Learning; Necrosis; NF-kappa B; Rats; Rats, Sprague-Dawley; Signal Transduction; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

To evaluate the functional and histological effects of ganglioside G(M1) and erythropoietin after experimental spinal cord contusion injury.. Fifty male Wistar rats underwent experimental spinal cord lesioning using an NYU-Impactor device and were randomly divided into the following groups, which received treatment intraperitoneally. The G(M1) group received ganglioside G(M1) (30 mg/kg); the erythropoietin group received erythropoietin (1000 IU/kg); the combined group received both drugs; and the saline group received saline (0.9%) as a control. A fifth group was the laminectomy group, in which the animals were subjected to laminectomy alone, without spinal lesioning or treatment. The animals were evaluated according to the Basso, Beattie and Bresnahan (BBB) scale, motor evoked potential recordings and, after euthanasia, histological analysis of spinal cord tissue.. The erythropoietin group had higher BBB scores than the G(M1) group. The combined group had the highest BBB scores, and the saline group had the lowest BBB scores. No significant difference in latency was observed between the three groups that underwent spinal cord lesioning and intervention. However, the combined group showed a significantly higher signal amplitude than the other treatment groups or the saline group (p<0.01). Histological tissue analysis showed no significant difference between the groups. Axonal index was significantly enhanced in the combined group than any other intervention (p<0.01).. G(M1) and erythropoietin exert therapeutic effects on axonal regeneration and electrophysiological and motor functions in rats subjected to experimental spinal cord lesioning and administering these two substances in combination potentiates their effects.

Topics: Animals; Drug Therapy, Combination; Erythropoietin; G(M1) Ganglioside; Injections, Intraperitoneal; Locomotion; Male; Models, Animal; Necrosis; Neuroprotective Agents; Random Allocation; Rats, Wistar; Reaction Time; Recovery of Function; Spinal Cord Injuries

Results of in vivo studies have shown erythropoietin (EPO) is associated with anti-inflammatory, anti-apoptotic, and cell protective effects on wound healing. These effects are dose-dependent. The aim of this study was to evaluate whether the duration of EPO treatment affects the healing process in the ischemic wound. Forty-two (42) Sprague-Dawley rats were anesthetized, wounded with H-shaped flaps, and randomized to 2 groups; Group 1 received 400 u/kg/day EPO and Group 2 received a saline solution, both via intraperitoneal injection following the wounding. All substances were administered once daily at the same time for up to 10 days after surgery. At days 3, 5, and 10, 7 rats from each group were sacrificed. Skin samples were stained with hematoxylin/eosin, viewed under an optical microscope at 10X and 40X magnification, and analyzed by blinded investigators for re-epithelialization, neovascularization amount and maturation of granulation tissue, inflammatory cells, and ulcer healing using an evaluation scale where 0 = none; 1 = partial; 2 = complete, but immature/thin: and 4 = complete and mature. Blood hemoglobin and hematocrit levels also were measured. Data were analyzed using ANOVA one-way test (P <0.05). Hemoglobin and hematocrit levels rose while subsequent doses of EPO were administered over time, accompanied by a transient surge in healing on day 5, when differences in healing scores were significant. Flap necrosis, ulceration, and abscess were noted on post-wounding day 10 near the pedicle. The study showed EPO therapy can improve wound healing early in the post-wounding period but can reduce wound healing after post-injury treatment day 5. Further research is necessary, particularly to establish how EPO influences the microcirculation and rheology.

Topics: Animals; Anti-Inflammatory Agents; Erythropoietin; Hematocrit; Hemoglobins; Ischemia; Microcirculation; Necrosis; Rats; Rats, Sprague-Dawley; Surgical Flaps; Wound Healing

Recent findings have attested to EPO tissue-protective effects in ischemically challenged tissues. Therefore, the study aimed at elaborating the effect of systemic pre- and postconditioning using EPO in a mouse model of persistent ischemia of the skin.. Three groups of nine C57Bl/6-mice each were analyzed. The experimental groups consisted of untreated controls, EPO preconditioning, and EPO postconditioning (500 IU EPO/kg bw/day for 10 days). Critically perfused skin flaps undergoing necrosis, if kept untreated, were mounted into dorsal skinfold chambers. Intravital epi-fluorescence microscopy was performed for 10 days to assess tissue necrosis, microcirculation, inflammation, and angiogenesis. Protein expression analysis of eNOS was performed. Hematocrit analyses were carried out separately in eight animals.. Only EPO preconditioning was able to significantly reduce necrosis, when compared with controls. This correlated with a significantly increased CD in the critically perfused tissue. Administration of EPO only slightly increased eNOS expression at day 10, when compared with controls. EPO induced angiogenesis and increased hematocrit. Finally, EPO significantly reduced leukocytic inflammation in arterioles in all EPO receiving mice.. EPO preconditioning effectively reduces skin necrosis predominantly by capillary maintenance and reperfusion, as well as improved tissue regeneration. Thus, EPO preconditioning might represent a promising, non-invasive approach to reduce complications in ischemically challenged skin.

Topics: Animals; Erythropoietin; Ischemia; Mice; Necrosis; Neovascularization, Physiologic; Skin; Time Factors

To improve cellular cardiomyoplasty efficacy after myocardial infarction (MI), we postulated that combining mesenchymal stem cells (MSCs) transplantation with anti-apoptotic and angiogenic effects of erythropoietin (EPO) and vascular endothelial growth factor (VEGF) may provide better prognosis in an infarcted heart 48 rats, underwent left anterior descending artery ligation, were divided into eight groups and treated as follows: Group 1: MSC+EPO+VEGF, Group 2: MSC+EPO, Group 3: MSC+VEGF, Group 4: MSC, Group 5: EPO+VEGF, Group 6: EPO, Group 7: VEGF and Group 8: Control. After MI induction, EPO and VEGF were injected subcutaneously at the dose of 3000 U/kg and 3 µg/kg respectively. MSCs were transplanted one week after MI. In the fourteenth and sixteenth days after infarction, EPO was injected again. Echocardiography demonstrated that all treatments improved left ventricular function significantly (before vs. after treatment) but in control group ejection fraction deteriorated over the 2-months period. Percent of ejection fraction recovery in all treatment groups were significantly greater than control (P<0.05). Compared with the control group, all treatments attenuated cell death in peri-infarct areas significantly, except groups 6 and 7. Vascular density of all treatment groups were more than control group but this superiority was statistically significant only in group 1 (P<0.01). All of our treatments had beneficial effects to some extent but MSC transplantation combined with EPO and VEGF administration resulted in superior therapeutic outcome in enhancing cell survival and neovascularization.

Topics: Animals; Apoptosis; Cardiomyoplasty; Cell Culture Techniques; Cell Separation; Combined Modality Therapy; Electrocardiography; Erythropoietin; Male; Mesenchymal Stem Cell Transplantation; Myocardial Infarction; Myocytes, Cardiac; Necrosis; Neovascularization, Physiologic; Phenotype; Prognosis; Rats; Rats, Wistar; Treatment Outcome; Vascular Endothelial Growth Factor A

To investigate whether systemic erythropoietin administration can prevent secondary burn progression in an experimental model and to elucidate the underlying mechanisms.. Prospective study.. University-based laboratory research.. Twenty-one male Wistar rats.. The burn comb model creates four rectangular burned surfaces that are intercalated by three unburned zones (interspaces) prone to secondary necrosis. Twenty-one animals were randomized to three experimental groups: 1) Local cooling with water for 20 minutes (control, 17°C); 2) and 3) local cooling with water and intraperitoneal erythropoietin once a day for five days starting 45 minutes after burn injury (500 IU/kg body weight: EPO 500 or 2500 IU/kg body weight: EPO 2500).. Secondary burn progression-both in depth (histology) and in surface (planimetry)-as well as interspace perfusion (laser Doppler flowmetry) and hematocrit were analyzed. Further, dilatory response (inducible nitric oxide synthase expression), inflammation (leukocyte count), and angiogenesis (CD31 expression) were assessed. Finally, wound healing time and contracture rate were reported. Burn progression resulted in complete dermal destruction as well as in important interspace necrosis in control animals, whereas burn progression was significantly reduced in a dose-dependent manner in animals treated with erythropoietin. Tissue protection was associated with an increased interspace perfusion with EPO 500, but not with EPO 2500, and was paralleled by a significant increase in inducible nitric oxide synthase expression and decreased inflammation, independent of the erythropoietin dosage. EPO 2500 led to a significant increase of hematocrit at day 4. Finally, faster wound healing and less contracture were observed in animals treated with EPO 500 only.. Erythropoietin represents an easy-to-use therapeutic approach to prevent secondary burn progression, i.e., to control damage after burn injury. It preserves microcirculatory perfusion within the endangered areas in a dose-dependent manner.

Topics: Animals; Burns; Disease Models, Animal; Disease Progression; Erythropoietin; Male; Necrosis; Neovascularization, Physiologic; Oxidative Stress; Prospective Studies; Random Allocation; Rats; Rats, Wistar; Wound Healing

Tubulointerstitial inflammation is the characteristics of renal ischemia reperfusion injury (IRI) that is inevitable in kidney transplantation. Erythropoietin (EPO) has recently been shown to have protective effects on renal IRI by anti-apoptosis and anti-oxidation. Here, the effect and mechanism of EPO on renal IRI were further investigated, with a focus on tubulointerstitial inflammation.. Male Sprague-Dawley rats were administrated with saline or EPO prior to IRI induced by bilateral renal pedicle clamping. Twenty-four hours following reperfusion, the effects of EPO on renal IRI were assessed by renal function and structure, tubulointerstitial myeloperoxidase (MPO) positive neutrophils, and proinflammatory mediator gene expression. The translocation and activity of NF-κB in renal tissues were also evaluated.. Compared with control groups, the EPO treated group exhibited lower serum urea and creatinine levels, limited tubular necrosis with a lower score of renal histological lesion. MPO positive cells in the tubulointerstitial area were greatly increased by IRI, but significantly reduced by the treatment of EPO. The gene expression of proinflammatory cytokines (IL-1β, IL-6, IL-10, and TNF-α) and chemokine (MCP-1) was also significantly decreased by EPO. In addition, less activation and nuclear-translocation of NF-κB was observed in the kidney treated by EPO as well.. EPO improved renal function and structure in IRI rats via reducing neutrophils in the tubulointerstitium, the production of proinflammatory cytokines and chemokine, as well as the activation and nuclear-translocation of NF-κB. EPO may have potential clinical applications as an anti-inflammation agent clinically for a wide range of injury.

Topics: Animals; Apoptosis; Creatinine; Cytokines; Erythropoietin; Kidney; Male; Models, Animal; Necrosis; Nephritis, Interstitial; NF-kappa B; Oxidative Stress; Peroxidase; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Damage control is essential in first aid of burn lesions. The aim of the present study was to investigate whether systemic erythropoietin (EPO) administration could prevent secondary burn progression in an experimental model.. The burn comb model creates four rectangular burn surfaces intercalated by three unburned zones prone to progression. Twenty-one Wistar rats were randomized to a control group or to receive intraperitoneal EPO (500 units per kg) once a day for 5 days starting 45 min (EPO45min) or 6 h (EPO6h) after burn injury. Histological analyses assessing burn depth, inflammation and neoangiogenesis, planimetric evaluation of burn progression, and laser Doppler flowmetry to assess perfusion were performed after 1, 4 and 7 days. Final scarring time and contracture rate were assessed once a week.. Burn progression was decreased significantly with EPO45min but not EPO6h; progression of burn depth stopped in the intermediate dermis (mean(s.e.m.) burn depth score 3·3(0·6) for EPO45min versus 4·7(0·3) and 5·0(0·0) for EPO6h and control respectively on day 7; P = 0·026) and the surface extension was significantly reduced (45(8), 65(4) and 78(4) respectively on day 7; P = 0·017). This was paralleled by faster re-establishment of perfusion with EPO45min (114(5) per cent on day 4 versus 85(6) and 91(3) per cent for EPO6h and control respectively; P = 0·096). The reduction in progression resulted in a decreased healing time (7·3(0·7) weeks for EPO45min versus 11·5(1·0) and 10·8(0·5) weeks for EPO6h and control; P = 0·020) and contracture rate (P = 0·024).. Early EPO prevented burn progression, mainly by improved vascular perfusion.

Topics: Animals; Blood Circulation; Burns; Contracture; Disease Progression; Erythropoietin; Hematinics; Hematocrit; Leukocyte Count; Male; Necrosis; Neovascularization, Physiologic; Nitric Oxide Synthase Type II; Random Allocation; Rats; Rats, Wistar; Recombinant Proteins; Wound Healing

Impaired wound healing in ischemic tissues such as skin flaps resulting from inefficient perfusion is one major cause of complications in plastic surgery. In present experimental study, we investigated the effects of fibroblast growth factor-2 (FGF-2 or bFGF) and erythropoietin (EPO) in prevention of skin flap necrosis in rats.. 30 adult albino rats were randomized into 3 groups: in control group, normal saline solution; in EPO group, erythropoietin (100U/kg/day); and in FGF-2 group, fibroblast growth factor-2 (2.5µg/day) were injected subcutaneously in 3 daily consecutive doses in the designated flap areas before creating 4:1 random pattern skin flaps on the dorsum of animals. Areas of ischemic (SI) and necrotic (SN) zones were measured and compared in all groups one week after the flap creations.. The necrotic zone (SN), as well as the ratio of the necrotic zone to the total discolored zone (SN/[SI+SN]) were substantially larger in the control group (41%±7%, 90%±6%) compared to the EPO (20%±2%, 42%±4%)  and the FGF-2 (8%±2%, 19%±3%) groups (p<0.001). The differences in these values were also meaningful between the EPO and FGF-2 groups (p<0.001).Vascular density in ischemic area of the control group was less than those in the EPO and the FGF-2 groups; however, the differences were not statistically significant between any of the groups (p>0.05).. Local administration of erythropoietin or fibroblast growth factor-2 in skin flaps could remarkably increase tissue viability and accelerate the wound healing process. However, the therapeutic effect of fibroblast growth factor-2 in preventing the necrotic event in ischemic zones of skin flaps is much more considerable than that of erythropoietin.

Topics: Angiogenesis Inducing Agents; Animals; Drug Administration Schedule; Erythropoietin; Fibroblast Growth Factor 2; Graft Survival; Injections, Subcutaneous; Ischemia; Male; Necrosis; Random Allocation; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Surgical Flaps; Wound Healing

Hyperglycemia is associated with a decreased tolerance to ischemia and an increased severity of renal ischemia reperfusion (I/R) injury. It has been suggested that erythropoietin (EPO) attenuates this effect in normoglycemic animals. This study sought to examine the effects of EPO on treatment renal I/R injury (IRI) in transiently hyperglycemic rats.. Twenty-eight male Wister rats anesthetized with isoflurane received glucose (2.5 g.kg(-1) intraperitoneally) before right nephrectomy. They were randomly assigned to four groups: sham operation (S); IRI (ISO); IRI+EPO, (600 UI kg(-1) low-dose EPO [EL]); and IRI+EPO 5000 UI kg(-1) (high-dose EPO [EH]). IRI was induced by a 25-minute period of left renal ischemia followed by reperfusion for 24 hours. Serum creatinine and glucose levels were measure at baseline (M1), immediately after the ischemic period (M2), and at 24 hours after reperfusion (M3). After sacrificing the animals, left kidney specimens were submitted for histological analysis including flow cytometry to estimate tubular necrosis and the percentages of apoptotic, dead or intact cells.. Scr in the ISO group was significantly higher at M3 than among the other groups. Percentages of early apoptotic cells in ISO group were significantly higher than the other groups. Percentages of late apoptotic cells in S and ISO groups were significantly greater than EL and EH groups. However, no significant intergroup differences were observed regarding the incidence of tubular necrosis.. Our results suggested that, although not preventing the occurrence of tubular necrosis, EPO attenuated apoptosis and glomerular functional impairment among transiently hyperglycemic rats undergoing an ischemia/reperfusion insult.

Topics: Animals; Apoptosis; Blood Glucose; Creatinine; Cytoprotection; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Flow Cytometry; Hyperglycemia; Kidney; Kidney Glomerulus; Kidney Tubules; Male; Necrosis; Nephrectomy; Rats; Rats, Wistar; Recombinant Proteins; Reperfusion Injury; Time Factors

During the early post transplant period, the tubular epithelium is the main target of injuries including ischemia reperfusion and toxicity effects from calcineurin inhibitors. Taking into account the tissue protective effects of erythropoietin mediated through its antiapoptotic properties, we tested whether administration of recombinant human erythropoietin protects against acute cyclosporine nephrotoxicity. Four groups of five rats were intraperitoneally treated over 28 days with 100UI/Kg/48h Epoetin beta (15mg/kg/day CsA diluted in olive oil, 100UI/Kg/48h Epoetin beta+15mg/kg/day CsA, or olive oil. Histological changes due to tubular necrosis were evaluated with Masson'Trichrome staining. Apoptotic nuclei in kidneys were detected using the Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling (TUNEL) method. Phospho-Akt, Akt, cleaved caspase 3 and non cleaved caspase 3 expression were evaluated using immunblotting. We demonstrate that recombinant human erythropoietin (epoetin beta) improves renal function and protects against acute tubular injury. Our data suggest that this nephroprotective effect is mediated by Akt activation and inhibition of tubular apoptosis. Indeed, western blotting analysis of caspase 3 cleavage and Akt phosphorylation demonstrates that rhEPO activate Akt signaling and inhibits caspase 3 cleavage induced by CsA. TUNEL staining confirms that rhEPO inhibits CsA-induced tubular apoptosis. In conclusion, we describe here a new potential target of recombinant human erythropoietin and our results provide an interesting framework for further nephroprotective therapies based on recombinant human erythropoietin.

Topics: Acute Disease; Animals; Apoptosis; Biomarkers; Blotting, Western; Caspase 3; Creatinine; Cyclosporine; Cytoprotection; Disease Models, Animal; Erythropoietin; Humans; In Situ Nick-End Labeling; Kidney Cortex Necrosis; Kidney Tubules; Male; Necrosis; Phosphorylation; Protective Agents; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Signal Transduction

Recent findings have attested the protective effects of erythropoietin (EPO) in ischemically challenged organs. We therefore aimed at elaborating the underlying mechanism of EPO-mediated protection in musculocutaneous tissue undergoing persistent ischemia after acute injury. Mice were assigned to five experimental groups equipped with a randomly perfused flap fixed in a dorsal skinfold chamber, whereas the sixth group did not undergo flap preparation: EPO, L-Name, EPO and L-Name, EPO and bevacizumab, untreated flap, and nonischemic chamber (control). Intravital fluorescence microscopic analysis of microhemodynamics, apoptotic cell death, macromolecular leakage and angiogenesis was carried out over a 10-day period. Further, immunohistochemical analysis was used to study the protein expression of endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF). Increased expression of eNOS in EPO-administered mice correlated with significant arteriolar dilation and thus increased blood flow resulting in a maintained functional capillary density (FCD) at day 10. In addition, EPO induced a VEGF upregulation, which was associated with newly formed capillaries. In addition, EPO was able to reduce ischemia-induced apoptotic cell death and finally to significantly reduce flap necrosis. In contrast, coadministration of L-Name abolished EPO-mediated tissue protection by abrogating the dilatory effect resulting in reduced FCD and tissue survival, without counteracting angiogenesis and apoptotic cell death, whereas additional administration of bevacizumab did not influence the beneficial effect of EPO on flap survival despite abrogating angiogenesis. Macromolecular leakage was found to be increased in all treatment groups. This study shows that EPO administration prevents musculocutaneous tissue from ischemic necrosis as a consequence of an eNOS-dependent arteriolar hyperperfusion maintaining capillary perfusion, thus representing a promising approach to pharmacologically protect ischemically challenged tissue.

Topics: Animals; Arterioles; Capillaries; Erythropoietin; Humans; Immunohistochemistry; Ischemia; Mice; Mice, Inbred C57BL; Microscopy; Muscle, Skeletal; Necrosis; Neovascularization, Physiologic; Nitric Oxide Synthase Type III; Recombinant Proteins; Regional Blood Flow; Skin; Surgical Flaps; Up-Regulation; Vascular Endothelial Growth Factor A

Intrauterine infection and inflammation have been causally linked to preterm birth and fetal brain injury. Using an ovine model of endotoxin-induced brain injury we have recently shown that recombinant human erythropoietin (rhEPO) reduces brain injury and protects against damage to myelination in major myelinated axon tracts. Our present objective was to determine whether rhEPO is also protective of the placenta and the fetal liver, organs which could influence fetal well-being. At 107 +/- 1 days of gestational age (DGA) chronically catheterized fetal sheep were randomly assigned to receive, on 3 consecutive days, either: 1) an i.v. bolus dose of lipopolysaccharide (LPS; approximately 0.9 microg/kg; n = 8); 2) i.v. bolus dose of LPS, followed at 1 h by 5000 IU/kg of rhEPO (LPS + rhEPO, n = 8); 3) rhEPO (n = 3). Seven untreated fetuses served as controls (n = 7). The placenta and fetal liver were examined histologically at 116 +/- 1 DGA; a placental injury index was formulated comprising measures of placental area, apoptosis, tissue injury and the size of the intervillous space. In LPS-exposed fetuses this index was greater than in control or rhEPO alone fetuses (p < 0.02). Treatment of LPS-exposed fetuses with rhEPO resulted in a reduction in the index (p < 0.05) and in the extent of liver necrosis. We conclude that rhEPO offers protection to the placenta and fetal liver in the presence of acute inflammation.

Topics: Animals; Erythropoietin; Female; Fetus; Humans; Inflammation; Lipopolysaccharides; Liver; Necrosis; Placenta; Pregnancy; Recombinant Proteins; Sheep

A noninvasive assessment of infarct size and transmural extension of myocardial infarction (TEMI) is fundamental in experimental models of ischemia-reperfusion. Conventional echocardiography parameters are limited in this purpose. This study was designed to examine whether speckle tracking imaging can be used in a rat model of ischemia-reperfusion to accurately detect the reduction of infarct size and TEMI induced by erythropoietin (EPO) as early as 24 h after reperfusion. Rats were randomly assigned to one of three groups: myocardial infarction (MI)-control group, 45 min ischemia followed by 24 h of reperfusion; MI-EPO group, similar surgery with a single bolus of EPO administered at the onset of reperfusion; and sham-operated group. Short-axis two-dimensional echocardiography was performed after reperfusion. Global radial (GS(r)) and circumferential (GS(cir)) strains were compared with infarct size and TEMI assessed after triphenyltetrazolium chloride staining. As a result, ejection fraction, shortening fraction, GS(r), and GS(cir) significantly correlated to infarct size, whereas only GS(r) and GS(cir) significantly correlated to TEMI. EPO significantly decreased infarct size (30.8 + or - 3.5 vs. 56.2 + or - 5.7% in MI-control, P < 0.001) and TEMI (0.37 + or - 0.05 vs. 0.77 + or - 0.05 in MI-control, P < 0.001). None of the conventional echocardiography parameters was significantly different between the MI-EPO and MI-control groups, whereas GS(r) was significantly higher in the MI-EPO group (29.1 + or - 4.7 vs. 16.4 + or - 3.3% in MI-control; P < 0.05). Furthermore, GS(cir) and GS(r) appeared to be the best parameters to identify a TEMI >0.75 24 h after reperfusion. In conclusion, these findings demonstrate the usefulness of speckle tracking imaging in the early evaluation of a cardioprotective strategy in a rat model of ischemia-reperfusion.

Topics: Animals; Echocardiography, Doppler; Erythropoietin; Models, Animal; Myocardial Infarction; Myocardium; Necrosis; Rats; Rats, Wistar; Reperfusion Injury; Salvage Therapy; Time Factors

Biliary obstruction and cholestasis result in hepatocellular necro-inflammation and lead to the development of liver fibrosis. The objective of this study was to analyze whether the multiple tissue-protective properties of erythropoietin are salutary in an experimental model of liver fibrosis. For this purpose, C57BL/6J mice underwent common bile duct ligation (BDL) and were treated with either darbepoetin-α (10 μg/kg i.p.) or physiological saline every third day, beginning 24 h after BDL. Mice were killed at 2, 5, 14, and 28 days after BDL. Beside hematological parameters, markers of inflammation and fibrosis were assessed histomorphometrically and immunohistochemically as well as by quantitative real-time PCR. In addition, a 7-week survival study was performed. BDL provoked cholestatic hepatitis characterized by biliary infarcts with accumulation of macrophages followed by marked collagen deposition and increased expression of profibrotic gene transcripts. Darbepoetin-α treatment significantly diminished the area of focal necrosis, reduced the infiltration of macrophages, decreased levels of profibrotic genes, and lowered collagen deposition. Moreover, darbepoetin-α significantly reduced systemic anemia caused by BDL. Finally, darbepoetin-α treatment significantly prolonged the survival time after BDL. This study suggests that darbepoetin-α, which is a clinically well-established substance, might be used as an efficient therapeutic option for patients with chronic cholestatic liver disease.

Topics: Alanine Transaminase; Anemia; Animals; Cholestasis, Extrahepatic; Collagen; Common Bile Duct; Cytophotometry; Darbepoetin alfa; Disease Models, Animal; Erythropoietin; Hematinics; Immunohistochemistry; Inflammation; Liver Cirrhosis; Mice; Mice, Inbred C57BL; Necrosis

Prothymosin-alpha (ProTalpha) causes a switch in cell death mode from necrosis to neurotrophin-reversible apoptosis in primary cultured cortical neurons. In the present study, post-ischemic administration (3 or 24 h, intravenously) of recombinant mouse ProTalpha without neurotrophins completely prevented ischemia-induced retinal damage accompanying necrosis and apoptosis, as well as dysfunction assessed by electroretinogram. Treatments with anti-erythropoietin (EPO) or brain-derived neurotrophic factor (BDNF) immunoglobulin G (IgG) reversed ProTalpha-induced inhibition of apoptosis. ProTalpha upregulated retinal EPO and BDNF levels in the presence of ischemia. Moreover, intravitreous administration of anti-ProTalpha IgG or an antisense oligodeoxynucleotide for ProTalpha accelerated ischemia-induced retinal damage. We also observed that ischemia treatment caused a depletion of ProTalpha from retinal cells. Altogether, these results suggest that the systemic administration of ProTalpha switches ischemia-induced necrosis to apoptosis, which in turn is inhibited by neurotrophic factors upregulated by ProTalpha and ischemia. ProTalpha released upon ischemic stress was found to have a defensive role in retinal ischemia.

Topics: Animals; Antibodies; Apoptosis; Brain-Derived Neurotrophic Factor; Erythropoietin; Ischemia; Male; Mice; Necrosis; Protein Precursors; Reperfusion Injury; Retina; Retinal Vessels; Thymosin

Erythropoietin (Epo), the primary regulator of erythropoiesis, has recently been shown to exert antiinflammatory and antiapoptotic properties in neuronal and myocardial tissue. We herein studied whether Epo pretreatment can reduce cell death and ischemic necrosis in a chronic in vivo model.. C57BL/6 mice were treated daily for 3 consecutive days with either 500 IU EPO/kg body weight (bw) (group Epo 500, n = 8) or 5000 IU EPO/kg bw (group Epo 5000, n = 8) administered intraperitoneally 24 hours before surgery. Thereafter, a random pattern myocutaneous flap subjected to acute persistent ischemia was elevated and fixed into a dorsal skinfold chamber. Flap elevation in animals receiving the water-soluble vitamin E analog Trolox (6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid) served as a nonspecific antiinflammatory agent control group (Tro); untreated control animals (Con) received saline only. Capillary perfusion, leukocyte-endothelial cell interaction, apoptotic cell death, and tissue necrosis were determined over a 10-day observation period using intravital multifluorescence microscopy.. Epo 5000 (44 +/- 26 cm/cm(2)) but, more noticeably, Epo 500 (116 +/- 32 cm/cm(2)) improved capillary perfusion compared with the two control groups, particularly the Con group (9 +/- 7 cm/cm(2); P < .05). The ischemia-associated leukocytic inflammation was found drastically attenuated in both Epo-pretreatment groups. Epo 500 further decreased apoptotic cell death and was effective in significantly reducing tissue necrosis (16% +/- 4% vs Tro: 48% +/- 7% and Con: 52% +/- 4%; P < .001). No angiogenic blood vessel formation could be observed in either of the Epo groups. Of interest, Epo 5000-but not Epo 500-increased systemic hematocrit.. Despite the lack of neovascularization, Epo pretreatment was capable of reducing ischemic tissue necrosis by protecting capillary perfusion, ie, nutrition of the tissue. Low-dose pretreatment was more effective, a result that was most likely due to the better perfusion conditions without an increase of the hematocrit values. Thus, low-dose Epo pretreatment might represent a promising strategy to protect critically perfused ischemic tissue.

Topics: Animals; Apoptosis; Cell Adhesion; Endothelial Cells; Endothelium, Vascular; Erythropoietin; Hematocrit; Ischemia; Leukocytes; Mice; Mice, Inbred C57BL; Microcirculation; Necrosis; Neovascularization, Physiologic; Receptors, Erythropoietin; Surgical Flaps

The objective of this study was to analyze whether erythropoietin (EPO) protects from necrosis of critically perfused musculocutaneous tissue and the mechanisms by which this protection is achieved.. EPO is the regulator of erythropoiesis and is used to treat patients with anemia of different causes. Recent studies suggest that EPO has also other tissue-protective effects, irrespective of its erythropoietic properties.. C57BL/6-mice were treated with 3 doses of EPO at 500 IU/kg intraperitoneally. EPO was given either before (preconditioning, n = 7), before and after (overlapping treatment, n = 7), or after (treatment, n = 7) surgery. Animals receiving only saline served as controls (CON). Acute persistent ischemia was induced by elevating a randomly perfused flap in the back of the animals. This critically perfused tissue demonstrates an initial microvascular failure of approximately 40%, resulting in approximately 50% tissue necrosis if kept untreated. Repetitive fluorescence microscopy was performed over 10 days, assessing angiogenesis, functional capillary density, inflammatory leukocyte-endothelial cell interaction, apoptotic cell death, and tissue necrosis. Additional molecular tissue analyses included the determination of inducible nitric oxide synthase, erythropoietin receptor (EPO-R), and vascular endothelial growth factor (VEGF).. EPO preconditioning did not affect hematocrit and EPO-R expression, but increased inducible nitric oxide synthase in the critically perfused tissue. This correlated with a significant arteriolar dilation, which resulted in a maintained functional capillary density (CON: 0 +/- 0 cm/cm(2); preconditioning: 37 +/- 21 cm/cm(2); overlapping treatment: 72 +/- 26 cm/cm(2); P < 0.05). EPO pretreatment further significantly reduced microvascular leukocyte adhesion and apoptotic cell death. Moreover, EPO pretreatment induced an early VEGF upregulation, which resulted in new capillary network formation (CON: 0 +/- 0 cm/cm(2); preconditioning: 40 +/- 3 cm/cm(2); overlapping treatment: 33 +/- 3 cm/cm(2); P < 0.05). Accordingly, EPO pretreatment significantly reduced tissue necrosis (CON: 48% +/- 2%; preconditioning: 26% +/- 3%; overlapping treatment: 20% +/- 3%; P < 0.05). Of interest, EPO treatment was only able to alleviate ischemia-induced inflammation but could not improve microvascular perfusion and tissue survival.. EPO pretreatment improves survival of critically perfused tissue by nitric oxide -mediated arteriolar dilation, protection of capillary perfusion, and VEGF-initiated new blood vessel formation.

Topics: Animals; Arterioles; Blotting, Western; Capillaries; Dilatation, Pathologic; Erythropoietin; Mice; Mice, Inbred C57BL; Microcirculation; Microscopy, Fluorescence; Necrosis; Neovascularization, Physiologic; Nitric Oxide Synthase Type II; Regional Blood Flow; Surgical Flaps; Vascular Endothelial Growth Factor A

Hypoxic-ischemic damage is a major challenge for neuronal tissue. In the present study, we investigated the effects of anoxia and glucose deprivation on adult neural stem cells (NSCs) in vitro. We assessed glucose deprivation, anoxia and the combination of the latter separately. After 24 h of anoxia, cell numbers increased up to 60% compared to normoxic controls. Whereas nearly all normoxic cells incorporated the mitotic marker BrdU (99%), only 85% of the anoxic cells were BrdU-positive. Counting of interphase chromosomes showed 8-fold higher cell division activity after anoxia. The number of necrotic cells doubled after anoxia (14% compared to 7% after normoxia). Apoptosis was measured by two distinct caspases assays. Whereas the total caspase activity was reduced after anoxia, caspase 3/7 showed no alterations. Glucose deprivation and oxygen glucose deprivation both reduced cell viability by 56 and 53%, respectively. Under these conditions, total caspases activity doubled, but caspase 3/7 activity remained unchanged. Erythropoietin, which was reported as neuroprotective, did not increase cell viability in normoxia, but moderately under oxygen glucose deprivation by up to 6%. Erythropoietin reduced total caspase activity by nearly 30% under all the conditions, whereas caspase 3/7 activity was not affected. Our results show that anoxia increases proliferation and viability of adult NSCs, although a fraction of NSCs does not divide during anoxia. In conclusion, anoxia increased cell viability, cell number and proliferation in NSCs from the rat brain. Anoxia turned out to be a highly stimulating environmental for NSCs and NSCs died only when deprived of glucose. We conclude that the availability of glucose but not of oxygen is a crucial factor for NSC survival, regulating apoptotic pathways via caspases activity other than the caspases 3/7 pathway. Therefore, we conclude that NSCs are dying from glucose deprivation, not from hypoxic-ischemic damage.

Topics: Animals; Apoptosis; Bromodeoxyuridine; Caspases; Cell Count; Cell Differentiation; Cell Hypoxia; Cell Proliferation; Cell Survival; Cells, Cultured; Erythropoietin; Glucose; Hypoxia-Ischemia, Brain; Male; Mitosis; Necrosis; Neuronal Plasticity; Neurons; Neuroprotective Agents; Rats; Rats, Wistar; Recovery of Function; Signal Transduction; Stem Cells

Erythropoietin (Epo) induces erythrocytosis by suppressing erythroid progenitor cell apoptosis through the Janus-activated kinase-signal transducers and activators of transcription (JAK-STAT) pathway. Since apoptosis contributes to cisplatin (CP)-induced nephrotoxicity and Epo receptors (EpoR) are expressed in the kidney, we examined the role of antiapoptosis in recombinant human erythropoietin (rHuEpo)-mediated renal protection. In human renal proximal tubular epithelial (RPTE) cells in culture, rHuEpo, but not inactive rHuEpo (I-rHuEpo), the receptor-binding sites of which are mutated, caused a significant reduction in CP-induced apoptosis at > or = 100 U/ml. rHuEpo, but not I-rHuEpo, increased STAT5 and Akt/PKB phosphorylation, demonstrating functional EpoR expression on RPTE cells. Furthermore, the JAK2 inhibitor tyrphostin AG-490 attenuated rHuEpo protection, suggesting a role of the JAK-STAT pathway in rHuEpo-mediated antiapoptosis. In rats, intravenous administration of 5,000 U/kg rHuEpo, but not an equivalent peptide mass of I-rHuEpo, before a single 5.5 mg/kg iv injection of CP, significantly increased hematocrit (Hct) and reduced the CP-induced increase in serum creatinine. Serum creatinine on day 4 was 3.4 +/- 0.3, 1.9 +/- 0.3, and 3.5 +/- 0.4 mg/dl in the CP, CP + rHuEpo, and CP + I-rHuEpo groups, respectively. Similarly, darbepoietin-alpha (DA), a hyperglycosylated analog of rHuEpo with prolonged in vivo activity when injected at 25 microg/kg iv before CP, significantly increased Hct and reduced serum creatinine. Renal clearance studies based on glomerular filtration rate and renal blood flow confirmed the significant renal protection by DA against CP. Tubular apoptosis and necrosis were significantly reduced in the kidneys of the CP + DA vs. the CP + saline group. Moreover, the equalization of Hct by venesection did not abrogate the DA-mediated renal protection. Administration of DA 48 h after CP injection also conferred significant renal protection. Thus our experiments confirm a role for erythropoiesis-stimulating proteins, including the new analog DA, in limiting CP-induced nephrotoxicity and suggest that antiapoptosis via the Epo-EpoR interaction is an important mechanism for renal protection.

Topics: Acute Kidney Injury; Animals; Antineoplastic Agents; Apoptosis; Cells, Cultured; Cisplatin; Darbepoetin alfa; Disease Models, Animal; Enzyme Inhibitors; Erythropoietin; Hematinics; Hematocrit; Humans; Janus Kinase 2; Kidney; Male; Necrosis; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Recombinant Proteins; STAT5 Transcription Factor; Tyrphostins

The administration of CD34-positive cells after stroke has been shown to have a beneficial effect on functional recovery by accelerating angiogenesis and neurogenesis in rodent models. Granulocyte colony-stimulating factor (G-CSF) is known to mobilize CD34-positive cells from bone marrow and has displayed neuroprotective properties after transient ischemic stress. This led us to investigate the effects of G-CSF administration after stroke in mouse. We utilized permanent ligation of the M1 distal portion of the left middle cerebral artery to develop a reproducible focal cerebral ischemia model in CB-17 mice. Animals treated with G-CSF displayed cortical atrophy and impaired behavioral function compared with controls. The negative effect of G-CSF on outcome was associated with G-CSF induction of an exaggerated inflammatory response, based on infiltration of the peri-infarction area with CD11b-positive and F4/80-positive cells. Although clinical trials with G-CSF have been started for the treatment of myocardial and limb ischemia, our results indicate that caution should be exercised in applying these results to cerebral ischemia.

Topics: Animals; Atrophy; Brain Ischemia; Data Interpretation, Statistical; Erythropoietin; Granulocyte Colony-Stimulating Factor; Immunohistochemistry; Mice; Middle Cerebral Artery; Necrosis; Neovascularization, Pathologic; Recombinant Proteins; Stroke; Treatment Outcome

This study was designed to evaluate the effect of recombinant human erythropoietin (rhEPO), insulin-like growth factor-1 (rhIGF-1) and epidermal growth factor (rhEGF) on ischemia-induced hair cell loss in an organotypic cochlea culture. The apical, middle and basal parts of the organs of Corti (newborn rat, postnatal days 3-5) were exposed to ischemia (3.5 h) in glucose-free artificial perilymph (pO2 10-20 mmHg) with or without growth factors. Controls were exposed to normoxia. Twenty-four hours after the onset of ischemia, the cultures were stained using tetramethyl rhodamine isothiocyanate (TRITC) phalloidin (hair cells), propidium iodide (membrane integrity) and apoptosis detection kit (DNA-fragmentation). Ischemia (3.5 h) induced a hair cell loss of 20 and 40% in the middle and basal cochlear parts, respectively, and an increase of the numbers of PI-stained and DNA-fragmented nuclei (controls 0-1, ischemia 4-7 nuclei/100 microm). The basal part was more affected than the apical one. rhEPO and rhIGF-1 significantly attenuated the ischemia-induced hair cell loss by reducing processes involved in apoptosis and necrosis. rhEPO has been in clinical use for more than a decade and found to be well tolerated. Therefore, rhEPO could be an effective drug for the prevention of hearing loss via a hair cell protective mechanism.

Topics: Animals; Animals, Newborn; Apoptosis; Epidermal Growth Factor; Erythropoietin; Hair Cells, Auditory; Humans; In Vitro Techniques; Insulin-Like Growth Factor I; Ischemia; Necrosis; Organ of Corti; Rats; Recombinant Proteins

Calciphylaxis occurred in a 40-year old female patient with end-stage renal failure. The patient developed livedo racemosa ("livedo reticularis") with painful skin necrosis and ulcers involving multiple areas of the hip and legs after 22 years of hemodialysis. X-ray-examinations revealed calcinosis of peripheral arteries, especially of the pelvis, thigh and hands, while histological examinations showed a fibrosis and calcinosis of small subcutaneous arteries. A generalized cutaneous microangiopathy could be demonstrated by transcutaneous oxygen pressure measurements. Laboratory data showed a moderate secondary hyperparathyroidism with mild elevation of calcium-phosphate product. In addition to the hemodialysis an attempt was made to improve the microcirculation by vasoactive drugs. The clinical course was characterized by slow healing of the ulcers and occurrence of new areas of cutaneous necrosis. Calciphylaxis is a rare late complication in patients with advanced, often end-stage renal failure. It has characteristic histopathological features and is frequently, but not always, associated with a disturbed calcium and phosphorus metabolism and mildly elevated levels of parathyroid hormone. Calciphylaxis is classified as a special type of metastatic calcinosis.

Topics: Adult; Aluminum Hydroxide; Calciphylaxis; Calcium; Cholecalciferol; Disseminated Intravascular Coagulation; Ergocalciferols; Erythropoietin; Female; Humans; Ischemia; Kidney Failure, Chronic; Long-Term Care; Necrosis; Parathyroid Hormone; Renal Dialysis; Skin Diseases, Vascular

The immature erythroid cell line J2E responds to erythropoietin (Epo) by proliferating and terminally differentiating into hemoglobin-synthesizing red blood cells. These cells produce a rapid, fatal erythroleukemia in mice characterized by hepatosplenomegaly and severe anemia. The aim of this study was to investigate the effects of murine interferons-alpha (MuIFN-alpha) on J2E cells in vitro and in vivo. Here we show that in culture MuIFN-alpha inhibited the Epo-induced proliferation of J2E cells but did not interfere with differentiation. When mice with J2E erythroleukemias were treated with MuIFNs in vivo, an extension of their life span was observed. Moreover, numerous necrotic lesions of infiltrating leukemic cells were detected in the spleens of these mice. Finally, ex vivo treatment of leukemic bone marrow cells with Epo and MuIFNs delayed mortality even further. It was concluded that MuIFNs (1) suppressed the proliferation of J2E cells in vitro but did not affect Epo-induced differentiation, and (2) inhibited the progress of erythroleukemias, especially in combination with Epo.

Topics: Animals; Cell Differentiation; Cell Division; Cell Line; Drug Resistance; Erythroid Precursor Cells; Erythropoietin; Female; Interferon-alpha; Leukemia, Erythroblastic, Acute; Mice; Necrosis; Spleen; Treatment Outcome

An unexpected case of nonocclusive mesenteric infarction in a patient on continuous ambulatory peritoneal dialysis is described. The common clinical finding in this entity is a low cardiac output state or even circulatory collapse. Nonocclusive mesenteric infarction has been reported very rarely during continuous ambulatory peritoneal dialysis, and only in the setting of cardiac dysfunction or prolonged hypotension. The current patient had none of the typical features commonly described in the clinical setting of nonocclusive mesenteric infarction; potential mechanisms, including the role of erythropoietin, in the genesis of this disorder are discussed.

Topics: Erythropoietin; Female; Humans; Infarction; Intestines; Kidney Failure, Chronic; Mesenteric Vascular Occlusion; Middle Aged; Necrosis; Peritoneal Dialysis, Continuous Ambulatory; Recombinant Proteins

Topics: Animals; Erythropoietin; Female; Hypoxia; Kidney Tubules, Proximal; Mercuric Chloride; Necrosis; Potassium Dichromate; Rats; Rats, Wistar; Reference Values; Urine

Butyric acid induces fetal hemoglobin (HbF), a property of potential therapeutic advantage in patients with disorders of globin chain synthesis. We performed dose escalation studies of this compound in baboons to assess whether clinically significant increases in HbF are achievable, and to define the associated toxicities. Additionally, the effect of butyrate in combination with erythropoietin on HbF induction was assessed. HbF induction in response to butyrate was dependent on the dose and duration of treatment. Doses of butyrate less than 4 g/kg/d were associated with minimal toxicity (hypokalemia) and significant HbF induction in these nonanemic animals, with 1 g/kg/d producing an increase in HbF-containing reticulocytes (F reticulocytes) from 0.9% to 8.7% and an increase in HbF from 0.8% to 1.4%. A dose of 2 g/kg/d resulted in an increase in F reticulocytes from 2.1% to 27.8% and an increase in HbF from 0.7% to 2.2%. Doses of 4 g/kg/d in another animal produced an increase in F reticulocytes from 1% to 21.6% and in HbF from 1.9% to 5.3%. Infusions in excess of 4 g/kg/d were complicated (after a variable amount of time) by a decreased level of alertness (caused by hyperosmolality or butyrate itself) and hematologic toxicity (with declines in reticulocyte, white blood cell, and platelet counts). Prolonged infusions of high doses of butyrate (8 to 10 g/kg/d) were associated with peak F reticulocyte percentages reaching 38% to 64.5% and HbF reaching levels in excess of 20%. These high doses (8 to 10 g/kg/d) were complicated in two animals with a striking and unique neuropathologic picture and, in one animal, multiorgan system failure. Erythropoietin in combination with butyrate, induced F reticulocytosis in an additive manner. We conclude that butyric acid is a strong inducer of HbF, particularly when administered in combination with erythropoietin. As chronic toxicities remain undefined, patients in future clinical trials of this and similar compounds should be monitored closely for evidence of neurologic toxicity.

Topics: Animals; Butyrates; Butyric Acid; Cerebellum; Dose-Response Relationship, Drug; Erythrocyte Count; Erythropoietin; Hematocrit; Hemoglobin, Sickle; Kinetics; Leukocyte Count; Medulla Oblongata; Necrosis; Papio; Platelet Count; Reticulocytes; Time Factors

Studies were conducted to determine whether the progressive development of anemia associated with the antineoplastic drug cis-diamminedichloroplatinum (cDDP) was the consequence of decreased erythropoietin (Epo) production due to cDDP-induced nephrotoxicity or selective inhibition of erythroid progenitor cells. Five days after a single intraperitoneal injection of cDDP, hypoxia-induced Epo production was not decreased in mice and was increased significantly in rats in spite of severe multifocal tubular necrosis. In both species, colony-forming units-granulocyte macrophage (CFU-gm) and colony-forming units-erythroid (CFU-e) were reduced significantly, with a greater decrease in CFU-e. Studies of an anemic patient receiving cDDP also showed elevated Epo and decreased CFU-gm and CFU-e. In vitro exposure of mouse and human bone marrow to cDDP caused a dose-dependent inhibition of CFU-gm and CFU-e in both species, with human CFU-e showing greatest sensitivity. The results indicate that the primary hematologic toxicity of cDDP is directed at the hematopoietic stem cell compartment.

Topics: Adult; Animals; Cisplatin; Erythropoietin; Hematopoietic Stem Cells; Humans; Kidney; Male; Mice; Necrosis; Rats

Topics: Alanine Transaminase; Anemia; Animals; Aspartate Aminotransferases; Bilirubin; Blood Cell Count; Blood Chemical Analysis; Blood Urea Nitrogen; Chemical and Drug Induced Liver Injury; Dogs; Erythropoietin; Female; Haplorhini; Hematocrit; Iron; Iron Isotopes; Kidney Diseases; Liver; Male; Mice; Necrosis; Nitrosamines; Polycythemia; Species Specificity