Teses em Neurociências e Biologia Celular (Doutorado) - PPGNBC/ICB

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2390

O Doutorado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).

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Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Caracterização do mecanismo de ação antiinflamatória do flavonóide BAS1 isolado da planta Brosimum acutifolium
(Universidade Federal do Pará, 2011-08-02) MORAES, Waldiney Pires; SILVA, Anderson Manoel Herculano Oliveira da; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971
Inflammation is the body's response to injury and danger. Even though it’s a body defensive mechanism, this response’s intensity and/ or persistency might be harmful for an individual. In such context, natural products are important sources of biologically active molecules, and they’re considered promising resources for the discovering of new drugs. Based on ethno pharmacological studies, BAS1 flavonoid (4'-hydroxy, 7, 8 - (2'', 2''-dimethyl-pyran)-flavan), which hasn’t been described by literature yet, was isolated from the Brosimum acutifolium plant, popularly known as "mururé da terra-firme." Facing this, the present study aimed at characterizing the anti-inflammatory mechanism of action of BAS1 flavonoid in stimulated murine macrophages. Macrophages were activated with LPS and IFN-γ, cell viability was evaluated by the MTT, levels of inflammatory mediators were determined by ELISA (TNF-α, PGE2, IL-10) through Griess reaction (NO) and protein expression by Western blotting. The results demonstrate that BAS1 only has cyclotoxic effects at high concentrations (100 μM) inhibited NO production (95%), negatively regulated the expression of NOS-2, reduced the TNF-α production (39%) and PGE2 (57%), but didn’t with IL-10 in activated macrophages. Thus, demonstrating the pharmacological effect of BAS1 flavonoid, as well as supporting the usage of the Brosimum acutifolium plant as an anti-inflammatory in our region was an important contribution from this study. Furthermore, the production of this plant’s extract could provide the local population with an effective and affordable anti-inflammatory. The present work may also contribute to the establishment of a new classification of anti-inflammatory agents, based on natural flavonoids, such as BAS1.
Acesso aberto (Open Access)
Estudo sobre o crescimento do tambaqui (Colossoma macropomom) submetido à dieta suplementada com camu camu (Myrciaria dubia) em água corrente e aquecida
(Universidade Federal do Pará, 2018-09) CANTO, Miguel Angelo de Oliveira; SALGADO, Claudio Guedes; http://lattes.cnpq.br/9601463988942971; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971
This study investigated the growth of the tambaqui (Colossoma macropomum) (Cm), an caracid teleost in the Amazon region, in the laboratory. Juvenile fish were submitted to the simulation of the natural conditions of feeding, climate and running water, corresponding to the flood and dry periods of the Amazonian hydrological cycle. In the flood, its diet is predominant of fruits and seeds, the environment is mild (28 ± 2°C) and the current is higher (0.2 to 0.3 m/s). In drought, the feed is based on animal protein, there is no current and the average temperature rises (34 ± 2°C). Therefore, the aim of this study was to investigate the effects of Myrciaria dubia (Md) on the growth of Cm in the drought or flood simulations with respect to the mild (28 ° C) or heated (34 ° C), standing or running water (0,2 or 0.3m/s), and diet with higher (45%) or lower (32%) crude protein (CP) content. For this, juveniles of Cm were acclimatized (70 or 126 days) in tanks of (310 or 500 liters) according to the experimental protocol. Protocol I: diet with fractioned daily supply (3x/day) and supplemented with Md; crude protein (45 or 32%); running water (0.2 m/s) or stopped at 28 or 34°C; analysis of muscle contents of IGF1 and total lipids. protocol II: single or fractioned offer (3x / day); standing or running water (0.3 m/s), intercalated, (12 hours) or continuous; quantification of the cavity fat mass. The results are presented on average plus or minus the standard error of the mean and compared by ANOVA plus Bonferrone post-test. Correlation test for weight, length or cavity fat versus running water; in the conditions of single or fractional supply was performed to verify interrelations between the phenomena studied. A potentiation of body mass expansion rather than length occurred by the diet supplemented with Md in standing and heated water. In contrast similar potentiation occurred for running and heated water in the 45% CP diet. In turn, lower growth performance (weight and length) was observed in the group submitted to a 32% CP diet. The running water also potentiated the accumulation of cavitary and muscular fat of total lipids, suggesting that the swimming effort demands accumulation of potential energy possibly related to the preservation of protein anabolism, since the protein content in the muscle tissue was not altered. On the other hand, the single daily supply of food was not enough to maintain the resulting growth performance to sustained swimming (running water). In the fractioned supply, the group submitted to continuous running water showed the best performance, suggesting that sustained swimming in running water may be a determinant factor for the growth of Cm if it is offered a diet with high protein content, considering the warm environment as the most favorable. Finally, the increased IGF-1 content in the muscle confirms the participation of this growth factor as the final pathway of humoral regulation of muscle hypertrophy. Hypertrophy results in increased swimming effort, and, surprisingly, in response to diet supplemented by Md.
Acesso aberto (Open Access)
Modulação dos sistemas GABAérgico e glutamatérgico na secreção hipotalâmica de ocitocina sob condições hiperosmóticas
(Universidade Federal do Pará, 2014-04-07) GRISÓLIA, Alan Barroso Araújo; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971
In mammals, the osmolality of extracellular fluid is a main factor for maintenance hydro electrolyte balance. Thus, changes in osmolality are detected by specialized hypothalamic cell, thereby starting a neurochemical signaling with glutamatergic and GABAergic system involvement, which may trigger the oxytocin release. However, the way of GABA glutamate aminoacids relationship could modulate the oxytocin release under hyperosmolality is till poorly understood. In this context, the aim in present study was characterize the hypertonic medium effect in GABA glutamate extracellular levels and its relationship with oxytocin release in the hypothalamus in vitro. For this, male wistar rats (270-300g) were kept under standard laboratory conditions. After decapitation, the brain was quickly removed and the hypothalamic fragments were immediately dissected in cold Krebs Ringer Bicarbonate Glucose Buffer (KRBG), and were transferred to perifusion chambers containing KRBG isotonic (280 mOsm/Kg H₂O), at flow rate of 0.5-1.0 ml/min, medium effluent was collected every during 15 min. The hypertonic stimulation (340 mOsm/kg H2O) was performed during 3 minutes. Glutamate, GABA and oxytocin levels were determined by reverse phase high-performance liquid chromatograph (HPLC) system. The measurements of glutamate showed an increased release only after decrease in GABA concentration. This release temporal profile motivated us to add GABA (3 mM) during osmotic stimulation, resulting in blockage of glutamate release previously observed. Moreover the results showed oxtocin release by hypertonic solution may also depend on a GABA decrease. The present study suggests that oxytocin release stimulated by hypertonicity depends on altering the relationship GABA / glutamate.
Acesso aberto (Open Access)
Modulação nitrérgica na regulação ocitocinérgica da secreção do peptídeo natriurético atrial em cardiomiócitos
(Universidade Federal do Pará, 2013-12-18) CONDE, Valney Mara Gomes; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971
Oxytocin (OT) was recently shown to be involved in endocrine and neuroendocrine regulation through receptor-mediated actions exerted on the heart, vasculature, and kidney. Oxytocin is a neuropeptide synthesized primarily in magnocellular neurons in the paraventricular and supraoptic nuclei of the hypothalamus, which project to posterior pituitary, median eminence, and several brain regions. Oxytocin is also produced in peripheral tissues, including the heart. In addition, nitric oxide (NO) may be generated constitutively within the heart. This work was performed to verify the role of oxytocin and nitrergic modulation on atrial natriuretic peptide (ANP) secretion in primary culture of mice embryo cardiac myocytes. Cardiomyocytes were isolated from Balb C mice embryo and cultivated by 3 days for obtain an optimal basal ANP secretion. After the exchange by a fresh medium containing OT (0.1, 1, 10 and 100 μM), a dose-dependent increase in ANP and nitrate release was observed, suggesting that OT may have a direct stimulatory action on cardiomyocytes and that action may be related to nitric oxide production. Blockage of 10 μM OT-induced ANP release were observed after addiction of 100 μM Compound VI [d(CH2)5, Tyr(Me)2, Thr4, Tyr-NH2(9)]-Ornitin Vasotocin (CVI-OVT), a specific OT antagonist. This antagonist induced a decrease in ANP release when added alone (100 μM), suggesting that OT may act by a tonic inhibitory autocrine mechanism on ANP secretion. A amplification of OT-induced ANP release was observed after addiction of 600 μM N(G) nitro-L-arginine methylester (L-NAME), a NO synthase inhibitor, and 100 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a soluble guanylate cyclase inhibitor, suggesting that a nitrergic negative feedback may act restraining the ANP release stimulated by OT.

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