Navegando por Palavras-chave "amino acids"
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- ItemSomente MetadadadosAmino acid and monoamine alterations in the cerebral cortex and hippocampus of mice submitted to ricinine-induced seizures(Elsevier B.V., 2002-07-01) Ferraz, A. C.; Anselmo-Franci, J. A.; Perosa, SR; Castro-Neto, E. F. de; Bellissimo, M. I.; Oliveira, B. H. de; Cavalheiro, E. A.; Naffah-Mazzacoratti, MDG; Da Cunha, C.; Univ Fed Parana; Fac Odontol; Universidade Federal de São Paulo (UNIFESP)The alkaloid ricinine isolated from the plant Ricinus communis, when administered to mice at high doses, induces clonic seizures accompanied by electroencephalographic alterations in the cerebral cortex and hippocampus. the lethal nature of ricinine-induced seizures is considered to be a good model for the study of the events that cause death during clonic seizures, particularly those related to respiratory spasms. the initial signs (pre-seizure period) were marked by exophthalmus and decreased locomotor behavior. Animals killed during the preseizure period presented an increased utilization rate (HVA/DA) of dopamine (DA), an increased concentration of noradrenaline (NA), and a decreased concentration of glutamate (Glu), glutamine (Gln), taurine (Tau), and serotonin (5-HT) in the cerebral cortex. the seizure period is characterized by the occurrence of hind limb myoclonus and respiratory spasms, which are followed by death. Alterations in the cerebral cortex concentration of these neurotransmitters persisted during the seizure period. These alterations are only partially observed in the hippocampus, mainly during the seizure period. the present results suggest that an increased release of Glu in the cerebral cortex can be implicated in the genesis of the ricinine-induced seizure and that it triggers many anticonvulsive mechanisms, like the release of Tau, DA, 5-HT, and NA. (C) 2002 Elsevier Science Inc. All rights reserved.
- ItemAcesso aberto (Open Access)Consumo de suplementos por alunos de academias de ginástica em São Paulo(Pontifícia Universidade Católica de Campinas, 2003-09-01) Pereira, Raquel Franzini; Lajolo, Franco Maria; Hirschbruch, Marcia Daskal [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)The increase in the number of fitness centers in the city of São Paulo, together with the increase in the offering of different supplements, has raised interest in the study of the consumption of supplements among fitness center users. The consumption of supplements by the general public has not been well quantified yet, and little information has been published about this subject. The arrival of new supplements in the market place has been faster than the creation of regulations and the accomplishment of researches proving their effects and determining the safety for their long-term use. In a sample of 309 users from seven fitness centers in São Paulo in 1999, 74 (23.9%) used at least one type of supplement, 77,0% of whom were male and 23,0% were female. The most consumed supplements were amino acids or other proteic products (38.9%), and the daily intake was the most mentioned consumption frequency (90.3%). The correlation between money expenditure with supplement and individual income was 27.5% (p = 0.0483; n = 52), and the expenses were greater among men; the correlation with family income was 36.1% (p = 0.0137; n = 46) and with Body Mass Index it was to 17.1% (p = 0.1564; n = 70). The conclusion was that the consumption of supplements is significant in the evaluated group, showing the need for more studies about the consumption of these products and their effects, focusing on nutrition education approaches in order to increase the level of information about them and to guarantee the safety of their use.
- ItemSomente MetadadadosExcitatory effects of nitric oxide within the rostral ventrolateral medulla of freely moving rats(Amer Heart Assoc, 1997-09-01) Pinge, Marli Cardoso Martins [UNIFESP]; Passy, Izabel Baraldi [UNIFESP]; Lopes, Oswaldo Ubriaco [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The aim of the present study was to examine the participation of NO in the rostral ventrolateral medulla (RVLM) of freely moving rats. We utilized NO donors and L-arginine, which were microinjected into the RVLM. Unilateral microinjection (100 nL) of 2.5 nmol sodium nitroprusside produced a biphasic response consisting of an initial, rapid increase in arterial pressure (AP) from 125+/-5 to 161+/-8 mm Hg (P<.01) and a second, long-lasting response with a progressive increase in AP (maximum Delta peak, 34+/-9 mm Hg; P<.01). Another NO donor, S-nitroso-N-acetylpenicillamine (SNAP; 2.5 nmol), also produced immediate hypertension from 118+/-5 mm Hg to 168+/-7 mm Hg (P<.01) but without the second, long-lasting response. L-Arginine (5, 24, and 140 nmol) produced a gradual increase in AP. L-Glutamate (5 nmol) microinjected into the RVLM produced an increase in AP from 122+/-9 mm Hg to 171+/-8 mm Hg (P<.01) and bradycardia from 342+/-10 to 315+/-8 beats/min. This AP response was significantly attenuated, from 115+/-7 to 128+/-9 mm Hg (P<.05), after microinjection of methylene blue (3 nmol) without alterations In heart rate. These results indicate that NO may have an excitatory effect on the RVLM of freely moving rats, probably in association with glutamatergic synapses via cGMP mechanisms.
- ItemSomente MetadadadosPositional-scanning combinatorial libraries of fluorescence resonance energy transfer peptides to define substrate specificity of carboxydipeptidases: assays with human cathepsin B(Elsevier B.V., 2004-12-15) Cotrin, S. S.; Puzer, L.; Judice, WAD; Juliano, L.; Carmona, A. K.; Juliano, M. A.; Universidade Federal de São Paulo (UNIFESP)We have developed positional scanning synthetic combinatorial libraries to define the substrate specificity of carboxydipeptidases. the library Abz-GXXZXK(Dnp)-OH, where Abz is ortho-aminobenzoic acid, K(Dnp) is N-c-2,4-dinitrophenyl-lysine with free carboxyl group, the Z position was successively occupied with 1 of 19 amino acids (eysteine was omitted), and X represents randomly incorporated residues, was assayed initially with human cathepsin B, and arginine was defined as one of the best residues at the P, position. To examine the selectivity of S-1(1) S-2, and S-3 subsites, the sublibraries Abz-GXXRZK(Dnp)-OH, AbzGXZRXK(Dnp)-OH, and Abz-GZXRXK(Dnp)-OH were then synthesized. the peptide Abz-GIVRAK(Dnp)-OH, which contains the most favorable residues in the P-3-P-1, positions identified by screening of the libraries with cathepsin B, was hydrolyzed by this enzyme with k(cat)/K-m = 7288 mM(-1) s(-1). This peptide is the most efficient substrate described for cathepsin B to this point, and it is highly selective for the enzyme among the lysosomal cysteine proteases. (C) 2004 Elsevier Inc. All rights reserved.
- ItemAcesso aberto (Open Access)Suplementação proteica não aumenta a concentração plasmática de óxido nítrico em homens saudáveis(Sociedade Brasileira de Medicina do Exercício e do Esporte, 2009-04-01) Moraes, Milton Rocha [UNIFESP]; Aoki, Marcelo Saldanha; Araújo, Ronaldo de Carvalho [UNIFESP]; Higa, Elisa Mieko Suemitsu [UNIFESP]; Mouro, Margaret Gori [UNIFESP]; Bacurau, Reury Frank Pereira; UMC Faculdade de Educação Física Laboratório de Aptidão Física; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Nutritional supplements, theoretically able to increase endogenous nitric oxide (NO) production have experienced great popularity among physically active individuals. AIM: scientific evidence available regarding this issue is scarce. Therefore, the purpose of this study was to evaluate the effect of a dietary supplement commercialized as a nitric oxide booster. MATERIALS AND METHODS: twelve sedentary men with no risk factors for cardiovascular diseases were supplemented with placebo or protein in two different occasions. The present study was conducted in a cross double-blind design. In order to assess plasmatic NO concentration, blood samples were obtained before (24hs and immediately before) and after (30 and 60 minutes) consumption of placebo (PLA) or protein supplement (SP). RESULTS: there was no difference in plasmatic nitric oxide concentration between both trails (Post-supplementation 30 min - PLA: 19.3±4.7 µmol.L-1 vs. SP: 18.9±4.4 µmol.L-1 and Post-supplementation 60 min - PLA: 21.3±6.5 µmol.L-1 vs. SP: 20.3±4.9 µmol.L-1). In addition, no difference was detected for arterial blood pressure. CONCLUSION: the dietary supplement analyzed in the present study failed to increase nitric oxide endogenous production.