Leukograms of healthy Holstein calves within the first month of life

To establish reference values and to assess the influence of age on the leukograms of healthy Holstein calves, blood samples were obtained from 300 animals. These samples were distributed equally (n=20) among 15 experimental groups according to age: birth to 8 hours, 9 to 16 hours, 17 to 24 hours, 2 days, 3 days, 4 days, 5 days, 6 to 7 days, 8 to 9 days, 10 to 11 days, 12 to 13 days, 14 to 15 days, 16 to 20 days, 21 to 25 days and 26 to 30 days of age. The maximum numbers of leukocytes (9,305.0/mL), segmented neutrophils (6,551.2/mL) and total neutrophils (6,678.3/mL) were noted within the first 8 hours of life, while band neutrophils peaked in number (133.3/mL) between 9 and 16 hours after birth. Meanwhile, the maximum total lymphocyte (4,992.1/µL) and typical lymphocyte (4,686.1/µL) counts occurred between 21 and 25 days, whereas atypical lymphocytes (388.5/µL) reached their maximum number between 26 and 30 days, demonstrating an inversion of the neutrophil:lymphocyte ratio over time. Thus, the influence of age on the leukocyte count of the evaluated calves was verified. The release of endogenous corticosteroids during labor or at birth may contribute to this variation in leukograms with age.

Erytrogram of healthy female Holstein calves during the first month of life

Benesi F.J., Teixeira C. M. C., Lisboa J.A.N., Leal M. L. R., Birgel Jr E. H., Bohland E. & Mirandola R. M. S. 2012. [Erytrogram of healthy female Holstein calves during the first month of life.] Eritrograma de bezerras sadias, da raca Holandesa, no primeiro mes de vida. Pesquisa Veterinaria Brasileira 32(4): 357-360. Departamento de Cl nica Medica, Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, Campus Universitario, Av. Prof. Dr. Orlando Marques de Paiva 87, Sao Paulo, SP 05508-000, Brazil. E-mail: febencli@usp.br In order to establish reference values, and to assess the in fluence of the age factor on the erytrogram of healthy Holstein calves, blood samples from 300 animals were used, spread over 15 experimental groups, according to age, in the first month of life. Variations of the average values for the components of erytrogram were as follows: number of red blood cells (x10(6)/mm(3)) = 6.68-7.60, packed cell volume (%) = 29.80-33.35, hemoglobin concentration (g/dl) = 9.00-10.43, mean corpuscular volume (fl) = 38.93-47.68, mean corpuscular hemoglobin (pg) = 11.75-14.69, mean corpuscular hemoglobin concentration (%) = 29.53-31.63% and number of reticulocytes (x10(3)/mm(3)) = 0.00-11.86. The in fluence of the age factor proved to be significant for the mean corpuscular volume, mean corpuscular hemoglobin and the number of reticulocytes.

Activation of the mitochondrial ATP-sensitive K+ channel reduces apoptosis of spleen mononuclear cells induced by hyperlipidemia

Background We have previously demonstrated that increased rates of superoxide generation by extra-mitochondrial enzymes induce the activation of the mitochondrial ATP-sensitive potassium channel (mitoKATP) in the livers of hypertriglyceridemic (HTG) mice. The resulting mild uncoupling mediated by mitoKATP protects mitochondria against oxidative damage. In this study, we investigate whether immune cells from HTG mice also present increased mitoKATP activity and evaluate the influence of this trait on cell redox state and viability. Methods Oxygen consumption (Clark-type electrode), reactive oxygen species production (dihydroethidium and H2-DCF-DA probes) and cell death (annexin V, cytocrome c release and Trypan blue exclusion) were determined in spleen mononuclear cells. Results HTG mice mononuclear cells displayed increased mitoKATP activity, as evidenced by higher resting respiration rates that were sensitive to mitoKATP antagonists. Whole cell superoxide production and apoptosis rates were increased in HTG cells. Inhibition of mitoKATP further increased the production of reactive oxygen species and apoptosis in these cells. Incubation with HTG serum induced apoptosis more strongly in WT cells than in HTG mononuclear cells. Cytochrome c release into the cytosol and caspase 8 activity were both increased in HTG cells, indicating that cell death signaling starts upstream of the mitochondria but does involve this organelle. Accordingly, a reduced number of blood circulating lymphocytes was found in HTG mice. Conclusions These results demonstrate that spleen mononuclear cells from hyperlipidemic mice have more active mitoKATP channels, which downregulate mitochondrial superoxide generation. The increased apoptosis rate observed in these cells is exacerbated by closing the mitoKATP channels. Thus, mitoKATP opening acts as a protective mechanism that reduces cell death induced by hyperlipidemia.