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	Provedor de dados BJMBR (4) Autor Markus,R.P. (4) Costa-Lotufo,L.V. (1) Freitas,J.C. (1) Garcia,C.R.S. (1) Hamassaki-Britto,D.E. (1) Hotta,C.T. (1) Kerchove,C.M. (1) Sampaio,L.F.S. (1) Zago,W.M. (1) Mais... Palavra-chave Melatonin (3) Nicotinic acetylcholine receptors (2) Alpha-bungarotoxin (1) Aplysia brasiliana (1) Calcium (1) Cholinergic systems (1) Circadian rhythm (1) Development (1) Host-parasite interaction (1) Malaria (1) Mecamylamine (1) Methyllycaconitine (1) Microphysiometry (1) Muscarinic acetylcholine receptors (1) Neuronal nicotinic acetylcholine receptors (1) Plasmodium (1) Retina (1) Trimethylsulfonium (1) Vas deferens (1) Mais... Tipo do documento Info:eu-repo/semantics/article (4) Ano 2005 (1) 2003 (1) 2002 (1) 1999 (1) País Brazil (4) Idioma Inglês (4)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 4 Primeira ... 1 ... Última Evaluation of the cholinomimetic actions of trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana (Gastropoda, Opisthobranchia) BJMBR Kerchove,C.M.; Markus,R.P.; Freitas,J.C.; Costa-Lotufo,L.V.. Trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana, negatively modulates vagal response, indicating a probable ability to inhibit cholinergic responses. In the present study, the pharmacological profile of trimethylsulfonium was characterized on muscarinic and nicotinic acetylcholine receptors. In rat jejunum the contractile response induced by trimethylsulfonium (pD2 = 2.46 ± 0.12 and maximal response = 2.14 ± 0.32 g) was not antagonized competitively by atropine. The maximal response (Emax) to trimethylsulfonium was diminished in the presence of increasing doses of atropine (P<0.05), suggesting that trimethylsulfonium-induced contraction was not related to muscarinic stimulation, but might be caused by... Tipo: Info:eu-repo/semantics/article Palavras-chave: Aplysia brasiliana; Trimethylsulfonium; Cholinergic systems; Muscarinic acetylcholine receptors; Nicotinic acetylcholine receptors. Ano: 2002 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000400013 Melatonin and N-acetyl-serotonin cross the red blood cell membrane and evoke calcium mobilization in malarial parasites BJMBR Hotta,C.T.; Markus,R.P.; Garcia,C.R.S.. The duration of the intraerythrocytic cycle of Plasmodium is a key factor in the pathogenicity of this parasite. The simultaneous attack of the host red blood cells by the parasites depends on the synchronicity of their development. Unraveling the signals at the basis of this synchronicity represents a challenging biological question and may be very important to develop alternative strategies for therapeutic approaches. Recently, we reported that the synchrony of Plasmodium is modulated by melatonin, a host hormone that is synthesized only during the dark phases. Here we report that N-acetyl-serotonin, a melatonin precursor, also releases Ca2+ from isolated P. chabaudi parasites at micro- and nanomolar concentrations and that the release is blocked by 250... Tipo: Info:eu-repo/semantics/article Palavras-chave: Malaria; Plasmodium; Calcium; Melatonin; Circadian rhythm; Host-parasite interaction. Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003001100016 Influence of melatonin on the development of functional nicotinic acetylcholine receptors in cultured chick retinal cells BJMBR Sampaio,L.F.S.; Hamassaki-Britto,D.E.; Markus,R.P.. The influence of melatonin on the developmental pattern of functional nicotinic acetylcholine receptors was investigated in embryonic 8-day-old chick retinal cells in culture. The functional response to acetylcholine was measured in cultured retina cells by microphysiometry. The maximal functional response to acetylcholine increased 2.7 times between the 4th and 5th day in vitro (DIV4, DIV5), while the Bmax value for [125I]-alpha-bungarotoxin was reduced. Despite the presence of alpha8-like immunoreactivity at DIV4, functional responses mediated by alpha-bungarotoxin-sensitive nicotinic acetylcholine receptors were observed only at DIV5. Mecamylamine (100 µM) was essentially without effect at DIV4 and DIV5, while dihydro-ß-erythroidine (10-100 µM) blocked... Tipo: Info:eu-repo/semantics/article Palavras-chave: Retina; Development; Nicotinic acetylcholine receptors; Alpha-bungarotoxin; Melatonin; Microphysiometry. Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000400015 Melatonin modulation of presynaptic nicotinic acetylcholine receptors located on short noradrenergic neurons of the rat vas deferens: a pharmacological characterization BJMBR Zago,W.M.; Markus,R.P.. Melatonin, the pineal hormone produced during the dark phase of the light-dark cycle, modulates neuronal acetylcholine receptors located presynaptically on nerve terminals of the rat vas deferens. Recently we showed the presence of high affinity nicotine-binding sites during the light phase, and low and high affinity binding sites during the dark phase. The appearance of the low affinity binding sites was due to the nocturnal melatonin surge and could be mimicked by exposure to melatonin in vitro. The aim of the present research was to identify the receptor subtypes responsible for the functional response during the light and the dark phase. The rank order of potency of agonists was dimethylphenylpiperazinium (DMPP) = cytisine &gt; nicotine &gt;... Tipo: Info:eu-repo/semantics/article Palavras-chave: Melatonin; Neuronal nicotinic acetylcholine receptors; Mecamylamine; Methyllycaconitine; Vas deferens. Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000800010 Registros recuperados: 4 Primeira ... 1 ... Última

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