Roxadustat Does Not Affect Platelet Production, Activation, and Thrombosis Formation

Objective: Roxadustat is a new medication for the treatment of renal anemia. EPO (erythropoietin)-the current treatment standard-has been reported to enhance platelet activation and production. However, to date, the effect of roxadustat on platelets is unclear. To address this deficiency, herein, we have evaluated the effect of roxadustat on platelet production and function. Approach and Results: We performed several mouse platelet functional assays in the presence/absence of in vitro and in vivo roxadustat treatment. Both healthy and 5/6 nephrectomized mice were utilized. The effect of roxadustat on platelet function of healthy volunteers and chronic kidney disease patients was also evaluated. For platelet production, megakaryocyte maturation and proplatelet formation were assayed in vitro. Peripheral platelet and bone marrow megakaryocyte counts were also determined. We found that roxadustat could not stimulate washed platelets directly, and platelet aggregation, spreading, clot retraction, and P-selectin/JON/A exposure were similar with or without in vitro or in vivo roxadustat treatment among both healthy and 5/6 nephrectomized mice. In vivo mouse thrombosis models were additionally performed, and no differences were detected between the vehicle and roxadustat treatment groups. EPO, which was considered a positive control in the present study, promoted platelet function and production as reported previously. Megakaryocyte maturation and proplatelet formation were also not significantly different between control mice and those treated with roxadustat. After receiving roxadustat for 14 days, no difference in the peripheral platelet count was observed in the mice. Conclusions: Administration of roxadustat has no significant impact on platelet production and function.

Haematopoietic effects of Angelica sinensis root cap polysaccharides against lisinopril-induced anaemia in albino rats

CONTEXT

Angelica sinensis L. (Umbelliferae) has medicinal properties.

OBJECTIVES

The present study evaluates the haematopoietic effects of A. sinensis polysaccharides (ASP) against lisinopril-induced anaemia.

MATERIALS AND METHODS

Thirty healthy adult male albino rats were randomly divided into five groups (n = 6). Group I was control group. Group II was treated with angiotensin-converting enzyme inhibitor (ACEI, 20 mg/kg/day) to induce anaemia. In group III, erythropoietin (EPO, 100 IU/kg/each) was administered in combination with ACEI. Group IV was treated with ASP (1 g/kg/day), extracted from A. sinensis root caps. In Group V, ASP (1 g/kg/day) was treated with ACEI. After 28 days, blood and tissue samples were collected for haematological and histopathological analysis, respectively.

RESULTS

The results showed that ACEI significantly reduced the haemoglobin (Hb, 10.0 g/dL), packed cell volume (PCV, 39.5%), red blood cells (RBCs, 6.2 million/mm³), mean corpuscular volume (MCV, 53.5 fL) and mean corpuscular haemoglobin (MCH, 16.2 pg/cell) values. In the group treated with ASP, the Hb (13.7 g/dL) and RBCs (7.8 million/mm³) increased significantly (p < 0.05). The combination of ASP and ACEI led to the significant (p < 0.05) reduction in Hb (10.7 g/dL), PCV (33.3%), RBCs (6.0 million/mm³), MCV (54.42 fL) and MCH (16.44 pg/cell) values. While histopathological examination of the liver and kidney cells showed a mild degree of toxicity in the ASP-treated group.

CONCLUSION

ASP has a potentiating effect on haematological parameters when given alone. However, when administered simultaneously with lisinopril, it showed an unfavourable effect with more complicated anaemia so it should not be used with ACEIs.

Iron-dextran injection into the substantia nigra in rats decreases striatal dopamine content ipsilateral to the injury site and impairs motor function

Iron chloride injections into the rat SNc can cause chronic decreases in striatal dopamine (DA) levels. However, changes in striatal DA content after iron-dextran injection into rat SNc have not been completely elucidated. The aim of this work was to measure striatal DA concentrations after iron-dextran injection into the SNc. We divided 40 male Wistar rats into five groups, including control, saline injected then sacrificed 7 days or 30 days later, and iron-dextran injected then sacrificed 7 days or 30 days later. Striatal DA content was measured in control animals and in all animals sacrificed 7 days or 30 days after injection, and motor performance was assessed in iron-dextran and saline injected groups 30 days after injection. The striatal DA levels were determined using HPLC. There were significant (P < 0.05) decreases in DA concentrations in the striatum ipsilateral to the injection site in the iron-dextran treated rats compared to control and saline-injected rats. There were no significant differences in DA concentration between the sham-operated (i.e., saline-injected) and control rats. We also observed motor deficits in the iron-dextran injected rats. The striatal DA reduction observed after iron-dextran injection may be attributable to iron-induced oxidative injury in the SNc. Motor deficits, in turn, may be explained by subsequent disturbances in striatal and cortical dopaminergic neuromodulation.

Peri- and postnatal rodent development of Hematide, an erythropoiesis-stimulating agent

BACKGROUND

Aperi- and postnatal reproduction toxicity study was conducted in rats treated with Hematide, a synthetic PEGylated peptidic erythropoiesis stimulating agent (ESA).

METHODS

Hematide, at IV doses of 0, 0.5, 3, and 15 mg/kg, was administered from implantation through lactation on gestation days (GDs) 5 and 18 and lactation day (LD) 13.

RESULTS

Hematide induced pronounced polycythemia in all Hematide-treated dams. On LDs 2 and 21, hemoglobin (Hgb) increases above control levels were 3.1, 5.2, and 5.0 g/dL and 4.1, 5.1, and 5.5 g/dL at the 0.5, 3, and 15 mg/kg/dose, respectively. There were no effects on parturition, lactation, or maternal behavior in the F0 generation female rats. A slight decrease in pup viability on postpartum days 2-4 and lower body weights and/or body weight gain for the F1 generation were associated with pronounced polycythemia and decreases in maternal body weight gain and/or food consumption at > or =3 mg/kg/dose. Hematide fetal exposure was negligible. No Hematide effect, other than on growth and survival, was noted on developmental, functional, mating, and fertility end points in the F1 generation rats, and no effect on litter or fetal parameters was observed in the F2 generation. The maternal no-observed-adverse-effect level (NOAEL) for Hematide was 0.5 mg/kg, and the NOAEL for parturition and maternal behavior was 15 mg/kg. The NOAEL for F1 pup viability and growth was 0.5 mg/kg/dose.

CONCLUSIONS

In conclusion, the Hematide-associated adverse findings were attributed to exaggerated erythropoiesis (pronounced and prolonged polycythemia) resulting from administration of an ESA to pregnant animals.

Parenteral iron compounds: potent oxidants but mainstays of anemia management in chronic renal disease

Ferric iron (Fe)-carbohydrate complexes are widely used for treating Fe deficiency in patients who are unable to meet their Fe requirements with oral supplements. Intravenous Fe generally is well tolerated and effective in correcting Fe-deficient states. However, the complexing of Fe to carbohydrate polymers does not block its potent pro-oxidant effects; systemic free radical generation and, possibly, tissue damage may result. The purpose of this review is to (1) underscore the capacity of currently used parenteral Fe formulations to induce oxidative stress, (2) compare the severity of these oxidant reactions with those that result from unshielded Fe salts and with each other, and (3) speculate as to the potential of these agents to induce acute renal cell injury and augment systemic inflammatory responses. The experimental data that are reviewed should not be extrapolated to the clinical setting or be used for clinical decision making. Rather, it is hoped that the information provided herein may have utility for clinical hypothesis generation and, hence, future clinical studies. By so doing, a better understanding of Fe's potential protean effects on patients with renal disease may result.

Reduction in transfusion requirements with early epoetin alfa treatment in pediatric patients with solid tumors: a case-control study

In a single-center, case-control study the authors evaluated the efficacy and safety of epoetin alfa in pediatric cancer patients receiving platinum- or nonplatinum-based chemotherapy. Thirty-seven patients with solid tumors received epoetin alfa 3 times weekly at a dose of 150 IU/kg (hemoglobin [Hb] > or = 12 g/dL and < or = 16 g/dL) or 300 IU/kg (Hb) < 12 g/dL) for 28 weeks. Data from treated patients were compared to data from 37 untreated control patients. Significant between-group differences in favor of the epoetin alfa-treated Patients were observed in overall red blood cell transfusion requirements (p = .007) and overall platelet transfusion requirements (p = .010). Additionally, significant between-group differences favoring epoetin alfa were seen by Kaplan-Meier plots, estimating mean time to first red blood cell transfusion (p = .0004). Mean Hb (g/dL) was maintained at baseline levels in the epoetin alfa group for most of the course of the study. No drug-related adverse events were seen in epoetin alfa-treated patients.

The absence of toxicity in intraperitoneal iron dextran administration: a functional and histological analysis

OBJECTIVE

To determine the influence of iron dextran intraperitoneal administration on the function and histology of the peritoneum in rats undergoing chronic peritoneal dialysis.

DESIGN

Prospective, randomized experimental study.

MATERIALS

Fifty-four Sprague-Dawley rats were divided into five groups: 3 study groups--high dose group (H), n = 12; intermediate dose (M), n = 12; and low dose group (L), n = 12--a dialysis control group (D), n = 12; and a tissue control (C), n = 7.

INTERVENTIONS

The study groups were given Dianeal containing iron dextran in a concentration of 0.5, 0.25, and 0.125 mg/L (groups H, M, and L respectively). Group D was given standard Dianeal. Group C was never dialyzed.

MAIN OUTCOME MEASURES

A 2-hour peritoneal equilibrium test (PET) was performed on the eighth day, at 3 months, and at 6 months. After the final PET, the animals were sacrificed and the peritoneal membrane was evaluated by gross inspection and light microscopy (silver, prussian blue, and trichrome staining).

RESULTS

Peritoneal transport of small solutes followed the same pattern in all groups, increasing over time. The peritonitis index was similar in the groups. No iron deposits or morphologic differences were seen in the gross inspection of the peritoneal cavity. No peritoneal iron deposition was detected in the histological analysis with prussian blue staining. No differences were noted in the light microscopic analysis of the mesothelial cell layer (silver staining), nor did the morphometric analysis of the submesothelial space show any differences in thickness between the groups.

CONCLUSION

These findings suggest the absence of toxic effects of iron dextran on the peritoneal cavity of rats in the concentrations studied. Further studies should be performed to evaluate the effectiveness of these dosages delivered intraperitoneally to maintain iron homeostasis.

Differential induction of polyamine oxidase activity in liver and heart of iron-overloaded rats

The present study was undertaken to investigate the effect of iron dextran treatment on polyamine oxidase (PAO) activity, iron accumulation, and lipid peroxidation in livers and hearts of rats. PAO catalyzes oxidative deamination of polyamines, the cellular aliphatic cations. This reaction produces highly toxic hydrogen peroxide, 3-acetamidopropanal, and precursors of higher polyamines. The rats were given iron dextran daily for 7 d. In iron-dextran-treated rats, a marked increase in the hepatic level of iron was associated with enhanced lipid peroxidation and increased PAO activity. Though iron accumulation and lipid peroxidation in the iron-treated rats increased significantly in the heart, PAO activity remained unchanged. The paraffin sections of livers stained with Perls iron stain showed the presence of iron in macrophages and hepatocytes. The sections of hearts showed iron deposits only in macrophages, while myocytes showed no iron staining. These results show that although iron dextran treatment results in accumulation of iron in both liver and heart, it induces PAO activity only in liver. The significance of increased PAO activity in lipid peroxidation and fibrosis in iron-mediated injury is discussed.

[Toxicologic study of the antianemia preparation dextrafer]

Experiments were conduced with a twofold purpose, viz--to determine the medium lethal dose of the preparation and to study the dextrafer distribution in tissues of rabbits after its single or repeated intravenous infusion. The medium lethal dose of the drug was found to be 250 time greater than its maximal therapeutic dose. Morphological and histochemical observations showed dextrafer to have no toxic effect on the rabbits' tissues over a period of 2 years after its single intravenous infusion.