Sixteen groups of mice were fed diets containing different selenium species to compare their toxicity. Inorganic sodium selenate and sodium hydroselenite, elementary nanoSe, organic Sel-Plex, and Lacto-MicroSelenium were administered for 14 d at concentrations of 0.5, 5, and 50 ppm Se, equivalent to 0.5, 5, and 50 mg Se/kg food, corresponding to an estimated 4, 40, and 400 µg/kg body weight/d Se uptake, respectively. At the end of the treatment, body, liver, spleen, kidney, heart, and brain weights were measured, mice were subjected to necropsy, and histological examinations were performed on the liver. At lower Se doses (0.5 and 5 ppm) a moderate reduction was observed in the number of bone marrow and white blood cells and in granulocyte-macrophage colony-forming units (GM-CFUs) relative to the untreated control group of mice. A comparison of lowest toxic doses of sodium selenite in mice (0.5 ppm) and mallard (10 ppm) indicates that birds are more resistant to Se than rodents. In mice, a small but measurable weight loss was observed after 5 ppm selenate and LactoMicroSe treatment. The most significant changes took place after 50-ppm administration in body and spleen weight, hematology, and liver histology. Toxicity was more pronounced when inorganic Se was applied than after subacute application of Sel-Plex, nanoSe, or LactoMicroSe. To summarize the effects, the authors' 14-d murine subacute toxicity study showed that the toxicity of Se species decreased in the following order: selenate > selenite > nanoSe > Sel-Plex > LactoMicroSe.

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Microrheological parameters show gender and age-related differences during intestinal I/R. These observations have importance in the planning and evaluation of experimental data.

Abstract. BACKGROUND:Age-and gender-related alterations of hemorheological parameters have not been completely elucidated to date. Experiments on older animals may give valuable information on this issue. However, the majority of rheological studies have been performed in young rodents. OBJECTIVE: We aimed to investigate the influence of aging and gender on hemorheological parameters in rats. METHODS: Coeval male (n = 10) and female (n = 10) Wistar (Crl:WI) rats were followed-up over 15 months. Blood samples were obtained from the lateral tail vein at 3, 4, 5, 9, 12, 15 and 18 months of age. Hematological parameters, red blood cell deformability (elongation under shear), osmotic gradient deformability and erythrocyte aggregation were tested. Body weight and the estrus cycle (in females) were also examined. RESULTS: Erythrocyte aggregation showed age-and gender-related variations. Red blood cell deformability was greater in females and gradually decreased over the 15-month period in both genders. Erythrocyte aggregation was greater in male rats at most ages, but did not show consistent changes with age. CONCLUSIONS: The micro-rheological parameters showed age-related alterations with gender differences. The effect of the estrous cycle cannot be excluded in female rats. The results provide reference data for studies of aging in rats and of the mechanism related to age and gender differences in hemorheology.

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RIPC alleviated several hemorheological changes caused by the liver I/R. However, the optimal timing of the RIPC cannot be defined based on these results.

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Podocytes are highly specialized, arborized epithelial cells covering the outer surface of the glomerular tuft in the kidney. Terminally differentiated podocytes are unable to go through cell division and hereby they are lacking a key property for regeneration after a toxic injury. Podocytes are long-lived cells but, to date, little is known about the mechanisms that support their stress resistance. Our aim was to investigate whether the well-known morphological changes during podocyte differentiation are accompanied by changes in oxidative resistance in a manner that could support their long-term survival. We used a conditionally immortalized human podocyte cell line to study the morphological and functional changes during differentiation. We followed the differentiation process for 14 days by time-lapse microscopy. During this period nondifferentiated podocytes gradually transformed into large, nonproliferating, frequently multinucleated cells, with enlarged nuclei and opened chromatin structure. We observed that differentiated podocytes were highly resistant to oxidants such as H2O2 and heme when applied separately or in combination, whereas undifferentiated cells were prone to such challenges. Elevated oxidative resistance of differentiated podocytes was associated with increased activities of antioxidant enzymes and H-ferritin expression. Immunohistochemical analysis of normal human kidney specimens revealed that podocytes highly express H-ferritin in vivo as well.