DETERMINAÇÃO DE TÉCNICAS DE AQUISIÇÃO DE SINAIS ELÉTRICOS CEREBRAIS EM BOVINOS UTILIZANDO EQUIPAMENTO TELEMÉTRICO

Os experimentos foram realizados na Faculdade de Zootecnia e Engenharia deAlimentos da Universidade de São Paulo, com duas novilhas da raça holandesa (2,5anos). Para que fossem determinadas técnicas ideais de aquisição de sinais cerebraisem bovinos adultos, utilizando equipamento telemétrico foram realizados testes deposicionamento e fixação de eletrodos superficiais e do equipamento de coleta.Determinadas a posição e forma de fixação dos eletrodos e do equipamento, foramrealizados experimentos com os animais totalmente livres dentro do piqueteexperimental. O sinal foi amostrado a 100 Hz e, devido à intensa movimentação doanimal apresentou grande quantidade de artefatos. Antes do cálculo da densidadeespectral de potências foram selecionados trechos livres de artefatos com 5 s deduração. As freqüências estavam de acordo com o apresentado na literatura, apesarde os autores utilizarem eletrodos de agulha e realizarem os experimentos combezerros. Os resultados indicaram que é possível adquirir sinal de EEG de bovinosadultos, utilizando equipamento telemétrico e eletrodos superficiais.

Effect of indole-3-acetic acid administration by gavage and by subcutaneous injection on rat leukocytes

This study was done to investigate the effect of indole-3-acetic acid (IAA) administered subcutaneously and by gavage on neutrophil function and cytotoxicity in neutrophils and lymphocytes. A gavage administration resulted in an increase in phagocytic capacity in neutrophils in a dose depended manner for 1 mg, 2 mg, 18 mg, and 40 mg of IAA per kg of body mass, respectively, compared with the control. Similarly, subcutaneous administration of IAA at 2, 18, and 40 mg per kg of body mass promoted a significant rise in phagocytosis by neutrophils. H2O2 production in neutrophils from treated rats by gavage was similar to those receiving subcutaneous IAA treatment, and did not show a significant difference between treatments and control. IAA treatment, whether by gavage or subcutaneous, did not produce an alteration in antioxidant enzyme activities or in glucose-6-phosphate dehydrogenase activity of either neutrophils or lymph nodes. Subcutaneous IAA administration did not alter the neutrophil and lymphocyte death as deduced by unaltered membrane integrity, DNA fragmentation and mitochondrial transmembrane potential, compared with controls. In conclusion, IAA administration either subcutaneously or by gavage could increase the phagocytic capacity by neutrophils and this acid administration did not have prooxidant effects or cytotoxic effects on neutrophils and lymphocytes.

Effect of Prototheca zopfii on neutrophil function from bovine milk

This study was carried to investigate neutrophil function in the presence of Prototheca zopfii. For this purpose, bovine milk neutrophils were incubated in the absence (control) of and presence of P. zopfii, and then they were examined hydrogen peroxide (H(2)O(2)) production, antioxidant enzyme activities, and phagocytic capacity. Milk was collected from negative "California Mastitis Test" (CMT) quarter from three lactating Holstein cows after induction of leukocytosis with an intramammary infusion of oyster glycogen. H(2)O(2) production was measured using the phenol red method. Catalase activity was measured following H(2)O(2) reduction at 240 nm and the activity of glutathione reductase was determined by measuring the rate of NADPH oxidation at 340 nm. P. zopfii death was assessed by fluorescent microscopy using acridine orange assay and by colony forming units (CFUs). Comparisons between the groups were initially performed by analysis of variance (ANOVA). Significant differences were then compared using Tukey's test with a significance coefficient of 0.05. Hydrogen peroxide production, catalase and glutathione reductase activities by neutrophils incubated in presence of P. zopfii were stimulated five times, 21% and 27% respectively, compared to the unstimulated-neutrophils. Neutrophils did not affect P. zopfii death as shown by microscopy and CFUs. These observations led to the conclusion that the P. zopfii promote a high increase of H(2)O(2) production by neutrophils from bovine milk during algae exposition accompanied by increase of antioxidant enzyme activities; however, this process did not affect P. zopfii death.

Effect of indole acetic acid administration on the neutrophil functions and oxidative stress from neutrophil, mesenteric lymph node and liver

This study was done to investigate the effect of the in vivo administration of indole acetic acid (IAA) on the neutrophil function, the activities of antioxidants enzymes in neutrophils, the mesenteric lymph node and on the oxidative stress in liver and plasma. The animals received subcutaneous administration of IAA in a phosphate-buffered saline (the control group received only the phosphate-buffered saline). The other groups received IAA at concentrations of 1 mg (T1), 2 mg (T2) and 18 mg (T3) per kg of body mass per day. Administration of IAA in both treatments T2 and T3 promoted a significant rise in the phagocytic capacity of neutrophils (by 51%), in comparison with the control. Another alteration was observed in antioxidant enzyme activities of the neutrophil and lymph node. But in the liver, the treatments imposed a significant decrease in the activity of catalase of 19% and 30% for T2 and T3, respectively, in comparison with the control. A similar effect was observed in the activity of hepatic glutathione peroxidase for T3 where a significant decrease of 31%, compared with the control, was obtained. The IAA did not show another significant alteration of the activities of superoxide dismutase and glutathione reductase activities in liver. The hepatic lipid peroxidation level, available by reactive products with thiobarbituric acid, has shown a significant decrease of 27% and 29% with T1 and T3 respectively, in comparison with the control. IAA treatment did not show a significant alteration in reduced glutathione contents in comparison with the liver and plasma controls. In conclusion, the IAA administration has a good potential animal utilization for increasing the phagocytic capacity with no prooxidant effect.