Protective effects of Tadalafil and darbepoetin against ischemia - reperfusion injury in a rat testicular torsion model

ABSTRACT Objectives: To evaluate protective effects of darbepoetin and tadalafil against ischemia-reperfusion injury in ipsilateral and contralateral testicle. Materials and Methods: Thirty 3-month-old adult male Wistar-Albino rats were randomly divided into 5 groups (A-E). Sham operation was performed in the first group. In Group B, rats did not received any medication after creating 720 degrees torsion of the left testis. The rats in Group C, D and E received darbepoetin, tadalafil, and darbepoetin/tadalafil combination 30 minutes after creating 720 degrees torsion of the left testis, respectively. The testes of rats in these three groups were detorsioned at 90 minutes after drug administration. Both testes were removed at 30 minutes after detorsion. Results: There were significant differences between the groups in terms of the degree of histopathological damage, Johnsen score, fibrosis score and caspase-3 immunoreactivity in the torsioned testes (p: 0.000). The results for each parameter in the left testes were significantly better in the darbepoetin / tadalafil combination group. Similarly, there were also significant differences in the contralateral testes (p: 0.000). Conclusion: The active substances darbepoetin and tadalafil that were used as a combination had protective effects on both testes and produced out better results in preserving testicular histology. Especially in cases where it is not possible to rescue the torsioned testis, this result was more noticeable in the contralateral testis.

Improvement in Erythropoieis-stimulating Agent-induced Pure Red-cell Aplasia by Introduction of Darbepoetin-alpha When the Anti-erythropoietin Antibody Titer Declines Spontaneously

Anti-erythropoietin antibodies usually cross-react with all kinds of recombinant erythropoietins; therefore, erythropoiesis-stimulating agent (ESA)-induced pure red-cell aplasia (PRCA) is not rescued by different ESAs. Here, we present a case of ESA-induced PRCA in a 36-yr-old woman with chronic kidney disease, whose anemic condition improved following reintroduction of darbepoetin-alpha. The patient developed progressive, severe anemia after the use of erythropoietin-alpha. As the anemia did not improve after the administration of either other erythropoietin-alpha products or erythropoietin-beta, all ESAs were discontinued. Oxymetholone therapy failed to improve the transfusion-dependent anemia and a rechallenge with ESAs continuously failed to obtain a sustained response. However, her anemia improved following reintroduction of darbepoetin-alpha at 3 yr after the initial diagnosis. Interestingly, anti-erythropoietin antibodies were still detectable, although their concentration was too low for titration. In conclusion, darbepoetin-alpha can improve ESA-induced PRCA when the anti-erythropoietin antibody titer declines and its neutralizing capacity is lost.

Safety and tolerability of darbepoetin alfa single intravenous administration in maintenance hemodialysis patients / 中华肾脏病杂志

Objective To investigate the safety and tolerability of darbepoetin alfa.a long-lasting erythmpoietin,single intravenous administration in maintenance hemodialysis(MHD) patients. Methods A single center,open clinical trial was carried out.Forty-three stable MHD patients were divided into 5 groups and received darbepoetin α at dosage of 0.225,0.45,0.9,1.8,3.6 μg/kg respectively.The vital signs,symptoms,ECG and laboratory examinations were monitored and detected before and after administration. Results Of the 43 patients (male 26and female 17),the largest tolerable dosage of darbepoetin alfa was 3.6 μg/kg.During the study,the main side effect associated with darbepoetin was hypertension aggravation(7%).One patient died but that was not associated with darbepoetin alfa. Conclusion Darbepoetin alfa is sale and well tolerated.

Pretreatment with Darbepoetin Attenuates Renal Injury in a Rat Model of Cisplatin-Induced Nephrotoxicity

BACKGROUND/AIMS: Darbepoetin alfa (DPO) exhibits comparable renoprotective effects to erythropoietin (EPO) in several animal models of acute renal injury. We examined whether DPO also attenuated renal injury in a rat model of cisplatin nephrotoxicity. METHODS: Male Spague-Dawley rats were divided into four groups: untreated, DPO-treated, cisplatin-injected, and DPO-treated cisplatin-injected. DPO pretreatment was conducted 24 hours after and just before cisplatin administration. Ninety-six hours after cisplatin administration, animals in all experimental groups were sacrificed. We examined serology; real-time reverse transcription polymerase chain reaction (RT-PCR) for TNF-alpha, Bcl-2, and MCP-1 gene expression; and Western blots for caspase-3. We also conducted terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and light microscopy. RESULTS: Pretreatment with DPO significantly reduced the levels of blood urea nitrogen and serum creatinine, the magnitude of renal tubular epithelial damage, and renal gene expression of TNF-alpha, Fas, and MCP-1 in kidneys injured by cisplatin. Pretreatment with DPO significantly increased Bcl-2 mRNA levels in kidneys injured by cisplatin, and significantly reduced activated caspase-3 and TUNEL-positive cells. CONCLUSIONS: DPO exhibits a renoprotective effect in experimental cisplatin-induced renal injury, the mechanism of which may involve DPO antiinflammatory and antiapoptotic effects.

Comparison of Erythropoietic Effect between Epoetin-alpha and Darbepoetin-alpha in Hemodialysis Patients: A Randomized Crossover Study / 대한신장학회지

PURPOSE: We aim to compare the erythropoietic effects of epoetin-alpha (EA, 4000 IU SC thrice a week) with those of darbepoetin-alpha (DA, 60ug IV weekly, conversion rate to EA=200:1). METHODS: Forty one stable hemodialysis patients were enrolled in this randomized crossover study. After a washout period of erythropoietin stimulating agents (ESA), the patients with hemoglobin (Hb) level of 11.0 g/dL, we stopped ESA. When Hb level decreased to 30% change in EA efficiency relative to DA efficiency. CONCLUSION: There was no significant difference in erythropoietic parameters for both EA and DA.

Efficacy of Darbepoetin alfa in Anemia Developed during Chemotherapy for Lung Cancer / 결핵및호흡기질환

BACKGROUND: Anemia is quite common in lung cancer patients and known to decrease the quality of life. Darbepoetin alfa is an erythropoiesis-stimulating protein approved for administration to cancer patients. This study examined the efficacy and safety of darbepoetin alfa in lung cancer patients with a hemoglobin concentration 10 g/dl. The efficacy and safety were measured by comparing the hemoglobin concentration and assessing the adverse events. RESULTS: After chemotherapy, the hemoglobin concentration decreased to 9.03+/-0.64 g/dl. With the darbepoetin alfa treatment, the hemoglobin concentration increased to 10.09+/-1.17 g/dl after 4 weeks reaching a peak hemoglobin concentration of 10.45+/-1.18 g/dl. The changes in hemoglobin after 4 and 8 weeks with treatment were 1.08+/-1.24 g/dl and 1.38+/-1.59 g/dl (p<0.01). At least a 1 g/dl or more increase in hemoglobin was observed in 62.4% of patients. There were no serious adverse effects except for some mild reactions. CONCLUSION: Darbepoetin alfa administered to lung cancer patients appears to be an effective, well-tolerated treatment for chemotherapy induced anemia.

Randomized, Controlled Trial of Darbepoetin Alfa for the Treatment of Renal Anemia in Hemodialysis Patients / 대한신장학회잡지

BACKGROUND: Darbepoetin alfa is a new erythropoietic agent with a three fold longer terminal half-life than recombinant human erythropoietin (r- HuEPO). The aim of this randomized, open-label study is to determine whether darbepoetin alfa is as effective as r-HuEPO for the treatment of anemia in hemodialysis patients when administered at a reduced dosing frequency. METHODS: A total 74 Korean hemodialysis patients receiving r-HuEPO therapy by either the intravenous (IV) or subcutaneous (SC) route were randomized to continue r-HuEPO or to receive an equivalent dose of darbepoetin alfa at a reduced dosing frequency. Patients receiving r-HuEPO once weekly changed to once every other week darbepoetin alfa, and those receiving r-HuEPO two or three times weekly changed to once-weekly darbepoetin alfa. The initial dose of darbepoetin alfa was based on the r-HuEPO dose at the time of entry into the study, using a formula equating the peptide mass of the two molecules (200 IU r-HuEPO=1 microgram darbepoetin alfa). The doses of r-HuEPO and darbepoetin alfa were titrated to maintain hemoglobin concentrations within -1.0 to +1.5 g/dL of patients' baseline values and within a range of 8.0 to 13.0 g/ dL for up to 20 weeks (16-week dose-titration period followed by a 4-week evaluation period). The primary end point was change in hemoglobin level between baseline and the evaluation period. RESULTS: The mean change in hemoglobin from baseline to the evaluation period was similar in the darbepoetin alfa (-0.03+/-0.19 g/dL) and r-HuEPO (0.27+/-0.20 g/dL) groups, and the difference between the two treatments was -0.30 g/dL (95% CI, -0.84 to 0.23). This was not a statistically significant or clinically relevant difference, despite the reduced frequency of darbepoetin alfa administration. The safety profiles of darbepoetin alfa and r-HuEPO were similar. CONCLUSION: This study suggests that darbepoetin alfa maintains hemoglobin as effectively as r- HuEPO, but with reduced dose frequency.