Navegando por Palavras-chave "monoamines"
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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.
- ItemSomente MetadadadosMoclobemide effects on prolactin plasma levels in healthy individuals: the hormonal increase induced by a single dose is maintained during a 4-week period of drug intake(Lippincott Williams & Wilkins, 1997-11-01) Juruena, M. F.; Pires, MLN; Calil, H. M.; Universidade Federal de São Paulo (UNIFESP)Neuroendocrine challenge studies are frequently used to study the pathophysiology of psychiatric illnesses and the effects of psychotropic drug treatment on brain monoamine function. Moclobemide, a reversible inhibitor of monoamine oxidase, with predominant effects on the A-type of the enzyme, was administered to 15 healthy men. Seven out of the 15 also received single blind placebo a week before the moclobemide. the individuals received moclobemide as a single dose (150 mg), followed by doses of 150 mg three times a day, during a 4-week period. Plasma prolactin was measured in the morning over a 150-min period, following the single dose, and then at the end of weeks 1, 2 and 4 of moclobemide intake. the present data show an acute and transitory increase of plasma prolactin levels after the single dose, and also during the long-term moclobemide administration. It might indicate that steady-state moclobemide levels, during the long-term drug administration, were low and thus large fluctuations of drug levels occurred between doses. Thus, it is suggested that larger doses or administering smaller doses more frequently, or both, may induce hyperprolactinaemia with clinical consequences.
- ItemSomente MetadadadosSerum level of serotonin during real and during exercise in paraplegic patients(Stockton Press, 1998-01-01) Steinberg, L. L. [UNIFESP]; Sposito, Maria de Matilde de Mello [UNIFESP]; Lauro, Flávio Antônio Ascânio [UNIFESP]; Tufik, Sergio [UNIFESP]; Mello, Marco Tulio de [UNIFESP]; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Cavalheiro, Esper Abrão [UNIFESP]; Silva, A. C.; Universidade Federal de São Paulo (UNIFESP); Univ Fed Goias CatalaoThe purpose of this study was to evaluate the serum level of serotonin (5-HT) during rest and response to exercise in subjects with spinal cord injury (SCI) with different levels of physical activity. Twenty-five male subjects with traumatic paraplegia, the neurological levels being between T1 and T12, volunteered for the study. They were divided into two groups matched for age, weight and time since injury, according to the level of physical activity: 14 inactive and 11 subjects regularly involved in sports activity and considered active. They all performed a maximal spiroergometric test with an arm crank ergometer. Two samples of blood were collected for 5-HT determination, during rest (PRE) and immediately after exercise test (POST). Serum 5-HT concentration was measured by high performance liquid chromatography using electrochemical detection (HPLC-ED). the results showed that peak oxygen uptake ((V) over dot O-2peak) was higher in the active group (27.08 +/- 2.60 vs 18.89 +/- 5.58 mL.kg(-1).min(-1), P<0.001). There were no significant differences between the inactive and active groups for the 5-HT PRE (respectively 176.96 and 193.73 ng.mL(-1), P>0.05) or POST values (275.44 vs 311.05 ng.mL(-1), P>0.05). Both groups showed an increment in 5-HT after maximal exercise, but only in the active group it reached statistical significance (Wilcoxon test, P<0.02). Our results show that chronic paraplegic individuals have normal resting serum serotonin levels and normal response to exercise. the relationship between training status, mood elevation and 5-HT in SCI could not be established in the present study, and further investigation is needed to clarify this issue.