Navegando por Palavras-chave "vasodilation"

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    GM1 ganglioside induces vasodilation and increases catalase content in the brain
    (Elsevier B.V., 2007-09-15) Furian, Ana Flavia; Oliveira, Mauro Schneider; Royes, Luiz Fernando Freire; Fiorenza, Natalia Gindri; Fighera, Michele Rechia; Myskiw, Jociane Carvalho; Weiblen, Rudi; Rubin, Maribel Antonello; Frussa-Filho, Roberto; Mello, Carlos Fernando; Universidade Federal de Sergipe (UFS); Univ Fed Rio Grande do Sul; Universidade Federal de São Paulo (UNIFESP)
    Monosialoganglioside (GM1) is a glycosphingolipid present in most cell membranes that displays antioxidant and neuroprotective properties. GM I increases catalase activity in cerebral cortices in vivo, but the mechanisms underlying this effect of GM I are not known. in the current study we investigated the effect of GM1 (50 mg/kg, ip) on the content of hemoglobin and catalase activity of hippocampus, cortex, and striatum of rats. GM I administration increased catalase activity and hemoglobin content in brain samples after 30 min, but had no effect on blood catalase activity. GM1-induced increase in catalase activity was abolished by brain perfusion with heparinized saline. Brain catalase activity in the absence of blood, estimated by regression analysis of data from perfused and nonperfused animals, was not altered by the systemic injection of GM1. Moreover, the addition of GM1 (30 or 100 mu M) did not increase catalase activity in slices of cerebral cortex in situ, further suggesting that blood circulation is required for this effect. the GM1-induced vasodilation was confirmed in vivo, because the systemic injection of GM1 (50 mg/kg, ip) increased (1.2-1.6 times) the width of pial vessels. (c) 2007 Elsevier Inc. All rights reserved.
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    Purification and partial characterization of kininogenase activity from Schistosoma mansoni adult worms
    (Cambridge Univ Press, 1998-10-01) Carvalho, W. S.; Lopes, C. T.; Juliano, L.; Coelho, PMZ; Cunha-Melo, JR; Beraldo, W. T.; Pesquero, J. L.; Universidade Federal de Minas Gerais (UFMG); Universidade Federal de São Paulo (UNIFESP)
    An enzyme presenting kallikrein-like activity (designated sK1) was purified from the supernatant of Schistosoma mansoni adult worm homogenate. the enzyme cleaves bradykinin from purified rat plasma kininogen. Activity was optimal at pH 9.0 and the enzyme showed amidolytic activity, since it hydrolysed the kallikrein synthetic substrate D-Pro-Phe-Arg-p-nitroanilide. the activity of sK1 upon rat plasma kininogen was strongly inhibited by the serine proteinase inhibitors phenylmethanesulfonyl fluoride, aprotinin or soybean trypsin inhibitor, but not by ethylenediaminetetraacetic acid or sodium tetrathionate. the molecular mass of sK1, as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, was 66 kDa and the pI value, estimated by analytical chromatofocusing, was 4.2. Physical and chemical properties suggest that sK1 is a serine proteinase of the kallikrein family. Evidence is presented which suggests that sK1 is a component of the tegumental surface of the parasite and the levels of its activity in the male adult worm are approximately 21 times higher than those in the female adult worm. the intravenous injection of 3 mu g of sK1 into an anaesthetized rat induced a drastic reduction in the arterial blood pressure of the animal. This effect lasted for about 1 min, and was followed by a progressive recovery of the arterial pressure. Neither bradycardia nor cardiac arrhythmias were noticed, suggesting a peripheral vasodilation effect. the presence of sK1 on the surface of adult male worms could play an important role in the wandering capacity of coupled worms into the visceral vasculature of the host.