Navegando por Assunto "NADPH desidrogenase"

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Acesso aberto (Open Access)
Distribuição das enzimas NADPH-Diaforase e Tirosina Hidroxilase na substância negra de camundongos infectados pelo Toxoplasma gondii
(Universidade Federal do Pará, 2010-06-29) MEURER, Ywlliane da Silva Rodrigues; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/3239362677711162; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978; MORAES, Antonio Marcos Mello; http://lattes.cnpq.br/2806117046911976
Toxoplasma gondii is a worldwide intracellular protozoan parasite and an important cause of disease in both humans and domestic animals. In Brazil, up to 80% of the population may be infected, depending on the region. Acute infection is generally asymptomatic, with posterior development of tissues cysts located mostly in muscles, retina and the central nervous system. The latent infection can alter behavior in animals and provoke psychotic symptoms in humans. Studies suggest that this infection may contribute to the occurrence of both schizophrenia and Parkinson’s disease, which are associated with abnormalities of the dopaminergic system. In this study we evaluated immunoreactivity for tyrosine hydroxylase (TH) and NADPH-diaphorase activities in the substantia nigra of infected male swiss mice. The animals were inoculated with bradyzoites (10 cysts) from a Toxoplasma gondii (Me-49 strain). The brains were removed after 30 and 60 days, sectioned and submitted to protocols to reveal NADPH-diaforase activity and immunohistochemistry anti-TH. The densitometric analysis showed a lower reactivity to NADPH-diaforase in the substantia nigra of infected animals when comparated with non-infected controls. A similar reduction was also observed in immunoreactivity against TH in the substantia nigra. These results indicate that T. gondii may change the dopaminergic system in infected brains.
Acesso aberto (Open Access)
Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats
(1998-09) OLIVEIRA, Ricardo Bezerra de; LEAL, Walace Gomes; NASCIMENTO, José Luiz Martins do; DINIZ, Cristovam Wanderley Picanço
The effects of methylmercury (MeHg) on histochemical demonstration of the NADPH-diaphorase (NADPH-d) activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1) and the other animals were perfused 6 months later (group 2). After microtomy, sections were processed for NADPHd histochemistry procedures using the malic enzyme method. Dendritic branch counts were performed from camera lucida drawings for control and intoxicated animals (N = 80). Average, standard deviation and Student t-test were calculated for each data group. The concentrations of mercury (Hg) in milk, fish and brain tissue were measured by acid digestion of samples, followed by reduction of total Hg in the digested sample to metallic Hg using stannous chloride followed by atomic fluorescence analysis. Only group 2 revealed a reduction of the neuropil enzyme activity and morphometric analysis showed a reduction in dendritic field area and in the number of distal dendrite branches of the NADPHd neurons in the white matter (P<0.05). These results suggest that NADPHd neurons in the white matter are more vulnerable to the long-term effects of MeHg than NADPHd neurons in the gray matter.