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Registros recuperados: 37 | |
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Schiaveto-de-Souza,A.; da-Silva,C.A.; Defino,H.L.A.; Bel,E.A.Del. |
Spinal cord injury is an extremely severe condition with no available effective therapies. We examined the effect of melatonin on traumatic compression of the spinal cord. Sixty male adult Wistar rats were divided into three groups: sham-operated animals and animals with 35 and 50% spinal cord compression with a polycarbonate rod spacer. Each group was divided into two subgroups, each receiving an injection of vehicle or melatonin (2.5 mg/kg, intraperitoneal) 5 min prior to and 1, 2, 3, and 4 h after injury. Functional recovery was monitored weekly by the open-field test, the Basso, Beattie and Bresnahan locomotor scale and the inclined plane test. Histological changes of the spinal cord were examined 35 days after injury. Motor scores were progressively... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spinal cord injury; Melatonin; Functional recovery. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000400348 |
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Di Mascio,P.; Dewez,B.; Garcia,C.R.S.. |
We have studied the effect of peroxynitrite (ONOO-) on the membrane cytoskeleton of red blood cells and its protection by melatonin. Analysis of the protein fraction of the preparation by SDS-PAGE revealed a dose-dependent (0-600 µM ONOO-) disappearance at pH 7.4 of the main proteins: spectrin, band 3, and actin, with the concomitant formation of high-molecular weight aggregates resistant to reduction by ß-mercaptoethanol (2%) at room temperature for 20 min. These aggregates were not solubilized by 8 M urea. Incubation of the membrane cytoskeleton with ONOO- was characterized by a marked depletion of free sulfhydryl groups (50% at 250 µM ONOO-). However, a lack of effect of ß-mercaptoethanol suggests that, under our conditions, aggregate formation is not... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Peroxynitrite; Melatonin; Spectrin; Protein; Ghost; Thiols. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000100002 |
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Nunes,D.M.; Mota,R.M.S.; Machado,M.O.; Pereira,E.D.B.; de Bruin,V.M.S.; de Bruin,P.F.C.. |
Disturbed sleep is common in chronic obstructive pulmonary disease (COPD). Conventional hypnotics worsen nocturnal hypoxemia and, in severe cases, can lead to respiratory failure. Exogenous melatonin has somnogenic properties in normal subjects and can improve sleep in several clinical conditions. This randomized, double-blind, placebo-controlled study was carried out to determine the effects of melatonin on sleep in COPD. Thirty consecutive patients with moderate to very severe COPD were initially recruited for the study. None of the participants had a history of disease exacerbation 4 weeks prior to the study, obstructive sleep apnea, mental disorders, current use of oral steroids, methylxanthines or hypnotic-sedative medication, nocturnal oxygen... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chronic obstructive pulmonary disease; Melatonin; Sleep. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008001000016 |
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Circadian organization means the way in which the entire circadian system above the cellular level is put together physically and the principles and rules that determine the interactions among its component parts which produce overt rhythms of physiology and behavior. Understanding this organization and its evolution is of practical importance as well as of basic interest. The first major problem that we face is the difficulty of making sense of the apparently great diversity that we observe in circadian organization of diverse vertebrates. Some of this diversity falls neatly into place along phylogenetic lines leading to firm generalizations: i) in all vertebrates there is a "circadian axis" consisting of the retinas, the pineal gland and the... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Circadian rhythms; Evolution; Vertebrates; Pineal; SCN; Retina; Melatonin. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000300003 |
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Bluhm,A.P.C.; Obeid,N.N.; Castrucci,A.M.L.; Visconti,M.A.. |
Vertebrates have a central clock and also several peripheral clocks. Light responses might result from the integration of light signals by these clocks. The dermal melanophores of Xenopus laevis have a photoreceptor molecule denominated melanopsin (OPN4x). The mechanisms of the circadian clock involve positive and negative feedback. We hypothesize that these dermal melanophores also present peripheral clock characteristics. Using quantitative PCR, we analyzed the pattern of temporal expression of Opn4x and the clock genes Per1, Per2, Bmal1, and Clock in these cells, subjected to a 14-h light:10-h dark (14L:10D) regime or constant darkness (DD). Also, in view of the physiological role of melatonin in the dermal melanophores of X. laevis, we determined... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Xenopus laevis; Dermal melanophores; Melatonin; Melanopsin; Per1; Per2; Bmal1; Clock. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000800007 |
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Ximenes,V.F.; Paino,I.M.M.; Faria-Oliveira,O.M.M. de; Fonseca,L.M. da; Brunetti,I.L.. |
Hypochlorous acid (HOCl) released by activated leukocytes has been implicated in the tissue damage that characterizes chronic inflammatory diseases. In this investigation, 14 indole derivatives, including metabolites such as melatonin, tryptophan and indole-3-acetic acid, were screened for their ability to inhibit the generation of this endogenous oxidant by stimulated leukocytes. The release of HOCl was measured by the production of taurine-chloramine when the leukocytes (2 x 10(6) cells/mL) were incubated at 37ºC in 10 mM phosphate-buffered saline, pH 7.4, for 30 min with 5 mM taurine and stimulated with 100 nM phorbol-12-myristate acetate. Irrespective of the group substituted in the indole ring, all the compounds tested including indole,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leukocytes; Myeloperoxidase; Hypochlorous acid; Indole ring; Melatonin; Indole-3-acetic acid. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005001100003 |
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Chuffa,L.G.A.; Amorim,J.P.A.; Teixeira,G.R.; Mendes,L.O.; Fioruci,B.A.; Pinheiro,P.F.F.; Seiva,F.R.F.; Novelli,E.L.B.; Mello Júnior,W.; Martinez,M.; Martinez,F.E.. |
Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight-1·day-1) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Melatonin; Ovary mass; Lipid peroxidation; Antioxidant defenses; Superoxide dismutase. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000300007 |
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Guney,Y.; Hicsonmez,A.; Uluoglu,C.; Guney,H.Z.; Ozel Turkcu,U.; Take,G.; Yucel,B.; Caglar,G.; Bilgihan,A.; Erdogan,D.; Nalca Andrieu,M.; Kurtman,C.; Zengil,H.. |
We investigated the day-night differences in intestinal oxidative-injury and the inflammatory response following total body (TB) or abdominopelvic (AP) irradiation, and the influence of melatonin administration on tissue injury induced by radiation. Rats (male Wistar, weighing 220-280 g) in the irradiated groups were exposed to a dose of 8 Gy to the TB or AP region in the morning (resting period - 1 h after light onset) or evening (activity span - 13 h after light onset). Vehicle or melatonin was administered immediately before, immediately after and 24 h after irradiation (10, 2.0 and 10 mg/kg, ip, respectively) to the irradiated rats. AP (P < 0.05) and TB (P < 0.05) irradiation applied in the morning caused a significant increase in thiobarbituric... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Irradiation; Melatonin; Circadian rhythm; Oxidative stress; Thiobarbituric acid reactive substances; Myeloperoxidase. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001000002 |
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Take,G.; Erdogan,D.; Helvacioglu,F.; Göktas,G.; Ozbey,G.; Uluoglu,C.; Yücel,B.; Guney,Y.; Hicsonmez,A.; Ozkan,S.. |
The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol) or melatonin administered 24 h before (10 mg/kg), immediately before (20 mg/kg) and 24 h after irradiation (10 mg/kg), all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05). Melatonin-treated groups showed less apoptosis as... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Testes; Gamma-irradiation; Melatonin; Immunohistochemistry; Electron microscopy. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000700006 |
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Ferreira,S.G.; Peliciari-Garcia,R.A.; Takahashi-Hyodo,S.A.; Rodrigues,A.C.; Amaral,F.G.; Berra,C.M.; Bordin,S.; Curi,R.; Cipolla-Neto,J.. |
The antioxidant and free radical scavenger properties of melatonin have been well described in the literature. In this study, our objective was to determine the protective effect of the pineal gland hormone against the DNA damage induced by cyclophosphamide (CP), an anti-tumor agent that is widely applied in clinical practice. DNA damage was induced in rats by a single intraperitoneal injection of CP (20 or 50 mg/kg). Animals received melatonin during the dark period for 15 days (1 mg/kg in the drinking water). Rat bone marrow cells were used for the determination of chromosomal aberrations and of formamidopyrimidine DNA glycosylase enzyme (Fpg)-sensitive sites by the comet technique and ofXpf mRNA expression by qRT-PCR. The number (mean ± SE) of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Melatonin; Cyclophosphamide; Chromosomal aberration; DNA fragmentation; Comet assay; Xpf expression. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000300278 |
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Shirinzadeh,Hanif; Ghalia,Mohammed; Tascioglu,Alev; Adjali,Ferial Intissar; Gunesacar,Gulsen; Gurer-Orhan,Hande; Suzen,Sibel. |
Melatonin (MLT) is a strong free radical scavenger that protects the body from the deleterious effects of excess oxidants. Synthesis of MLT analogue compounds with antioxidant potency has recently attracted the interest of researchers. In general, the strategy consists of modifying the groups in the different sites of the indole ring or replacing the indole ring with an analogue. As part of our ongoing research, the antioxidant capacity and cytotoxicity of newly synthesized MLT analogue naphthalene derivatives were evaluated. The radical scavenging activity was tested by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Most of the synthesized compounds showed significant antioxidant activity in comparison to MLT. The structure-activity relationship was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant; Cytotoxic; Melatonin; MTT; DPPH. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502020000100550 |
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Registros recuperados: 37 | |
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