864 resultados para INDUCED LOCOMOTOR-ACTIVITY
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In this study, a commercial enzyme immunoassay (EIA) was validated in detecting glucocorticoids in Pampas deer feces, in order to investigate the influence of several factors on the adrenocortical function. Fecal samples, behavioral data and information concerning male grouping and antlers status were collected at a monthly basis during a 1 year period from free-ranging stags living at Emas National Park, Brazil (18 degrees S/52 degrees W). The results revealed that concentrations of fecal glucocorticoids in winter were significantly higher than those corresponding to spring and summer. In addition, dry season data presented higher levels than during the wet season. Significant difference was found between fecal levels of breeding stags in summer and nonbreeding stags, whereas no difference was observed between breeding stags in winter and nonbreeding stags. on the other hand, males from areas with frequent human disturbance exhibited higher glucocorticoid concentrations and flight distances than individuals from areas of lower human activity. Males with antlers in velvet had elevated levels compared with animals in hard antler or antler casting. Also, we found that glucocorticoid levels were higher in groups with three or more males than in groups with only one male. The flight distances showed positive correlation with fecal glucocorticoid. These data indicate that fecal glucocorticoid provides a useful approach in the evaluation of physiological effects of environment, inter-individuals relationship and human-induced stressors on free-ranging Pampas deer stags. (c) 2005 Elsevier B.V. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The present study evaluated the hepatoprotective effect of an N-acetyl or-methionine + choline chloride + caffeine + thiamine hydrochloride + nicotinamide + pyridoxine hydrochloride compound at doses of 0.2, 0.6 and 1.0 mL/kg of b.w., and the assessment was done by the investigation of serum-enzymatic activity, metabolic functions of the liver and histophatological changes in female Wistar rats, which were subjected to experimental intoxication with CCl4. One hundred and nineteen rats were randomly distributed into 17 groups, performing five different treatments, being evaluated seven animals per treatment in four periods: 2, 4, 6 and 8 days after CCl4-induced intoxication. Treated rats with the hepatoprotective medicine (HM) presented a significant reduction in infiltration of inflammatory cells, steatosis, necrosis and liver congestion when compared to non-treated rats (control). Beside these results, the treatment showed a positive effect on circulatory alterations in the intoxicated animals, with reduction of spleen and renal congestion, as well as, promotion of a significant improvement in ALT, AST, LDH, ALP, GGT enzymatic serum activity reduction and in recovering liver function regarding the metabolism of urea, triglycerides and glucose. These findings indicate therapeutic usefulness of the compound when administered at dose 0.6 and 1.0 mL/kg of b.w. in female Wistar rats. (C) 2010 Elsevier GmbH. All rights reserved.
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A compactação é um dos fatores mais agravantes para a qualidade do solo, porém o seu efeito na comunidade e atividade enzimática microbiana não tem sido suficientemente estudado. Seis níveis de compactação foram obtidos pela passagem de tratores com diferentes pesos em um Latossolo Vermelho, e a densidade final foi medida. Amostras de solo foram coletadas nas profundidades de 0-10 e 10-20 cm, após a colheita do milho. O efeito da compactação foi evidente em todos os parâmetros estudados, mas nem sempre foi significativo. A contagem das bactérias totais reduziu significativamente em 22-30 %, e a das nitrificantes, em 38-41 %, no solo com maior densidade em relação ao controle. Contudo, a população de fungos aumentou de 55 a 86 %, e a das bactérias desnitrificantes, de 49 a 53 %. A atividade da desidrogenase diminuiu de 20 a 34 %; a da urease, de 44 a 46 %; e a da fosfatase, de 26 a 28 %. O conteúdo de matéria orgânica e o pH do solo diminuíram na camada 0-0,10 em relação à de 0,10-0,20 m e influíram possivelmente na redução das contagens microbianas exceto das bactérias desnitrificantes, e na atividade das enzimas, menos a da urease. Esses resultados indicam que a compactação do solo teve influência na comunidade de microrganismos aeróbios e na sua atividade. Esse efeito pode alterar a ciclagem de nutrientes e diminuir a produção da planta.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The relationships among avian uncoupling protein (avUCP) mRNA expression, heat production, and thyroid hormone metabolism were investigated in 7-14-day-old broiler chicks (Gallus gallus) exposed to a low temperature (cold-exposed chicks, CE) or a thermoneutral temperature (TN). After 7 days of exposure, CE chicks exhibited higher heat production (+83%, P < 0.01), avUCP mRNA expression (+20%, P < 0.01), and circulating triiodothyronine (T-3) levels (+104%, P = 0.07) for non-statistically different body weights and feed intake between 3 and 7 days of exposure as compared to TN chicks. Plasma thyroxine (T-4) concentration was clearly decreased in CE chicks (-33%, P = 0.06). The lower hepatic inner-ring deiodination activity (-47%) and the higher renal outer-ring deiodination activity (+75%) measured in CE compared to TN chicks could partly account for their higher plasma T3 concentrations. This study describes for the first time the induction of avUCP mRNA expression by low temperature in chickens, as it has been previously shown in ducklings, and supports the possible involvement of avUCP in avian thermogenesis. (C) 2003 Elsevier B.V. (USA). All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We evaluated the involvement of dorsal hippocampus (DH) 5-HT1A receptors in the mediation of the behavioral effects caused by the pharmacological manipulation of 5-HT neurons in the median raphe nucleus (MRN). To this end, we used the rat elevated T-maze test of anxiety. The results showed that intra-DH injection of the 5-HT1A/7 agonist 8-OH-DPAT facilitated inhibitory avoidance, an anxiogenic effect, without affecting escape. Microinjection of the 5-HT1A antagonist WAY-100635 was ineffective. In the elevated T-maze, inhibitory avoidance and escape have been related to generalized anxiety and panic disorders, respectively. Intra-MRN administration of the excitatory aminoacid kainic acid, which non-selectively stimulates 5-HT neurons in this brain area facilitated inhibitory avoidance and impaired escape performance, but also affected locomotion. Intra-MRN injection of WAY-100635, which has a disinhibitory effect on the activity of 5-HT neurons in this midbrain area, only facilitated inhibitory avoidance. Preadministration of WAY-100635 into the DH blocked the behavioral effect of intra-MRN injection of WAY-100635, but not of kainic acid. These results indicate that DH 5-HT1A receptors mediate the anxiogenic effect induced by the selective stimulation of 5-HT neurons in the MRN. (c) 2007 Elsevier B.V. and ECNP. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The protective effect of gallic acid and its esters, methyl, propyl, and lauryl gallate, against 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione (GSH) in erythrocytes was studied. The inhibition of hemolysis was dose-dependent, and the esters were significantly more effective than gallic acid. Gallic acid and its esters were compared with regard to their reactivity to free radicals, using the DPPH and AAPH/pyranine free-cell assays, and no significant difference was obtained. Gallic acid and its esters not only failed to inhibit the depletion of intracellular GSH in erythrocytes induced by AAPH but exacerbated it. Similarly, the oxidation of GSH by AAPH or horseradish peroxidase/H(2)O(2) in cell-free systems was exacerbated by gallic acid or gallates. This property could be involved in the recent findings on proapoptotic and pro-oxidant activities of gallates in tumor cells. We provide evidence that lipophilicity and not only radical scavenger potency is an important factor regarding the efficiency of antihemolytic substances.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)