Navegando por Assunto "Cortisol"

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Acesso aberto (Open Access)
Análise comportamental e eletrofisiológica do uso de glicocorticoides no sistema nervoso central em modelos animais de depressão
(Universidade Federal do Pará, 2017-01-31) CARDOSO, Keilla Gisele Mendonça; GOMES, Daniela Lopes; http://lattes.cnpq.br/0014255351015569; LIMA, Silene Maria Araújo de; CV: http://lattes.cnpq.br/8961057812067156
Dexamethasone is a glucocorticoid widely prescribed in Medicine, used as immunosuppressant and anti-inflammatory as well as fluoxetine, which is an antidepressant, serotonin reuptake, which can be used at some point while aiming their respective purposes. The aim of this study was to evaluate the electroencephalographic abnormalities in animals administered with these drugs as well as the behavioral effects evaluated in an animal model of depression, forced swimming. The study was conducted in adult male Wistar rats subjected to administration of dexamethasone acute dose of 4 mg/kg, 24 hours before electrocorticographic record, and chronic, administered for seven days every 24 hours at a dose of 4 mg/kg i.p. Fluoxetine was administered at a dose of 5 mg/kg, for seven days orally with a similar tool the orogastric tube, gavage procedure. After administration, the electroencephalographic parameters of drug activity were recorded and analyzed. When comparing the acute administration of dexamethasone with chronic, there were no statistical differences, but there was a trend towards decreased Theta and Gamma force for chronic use. The group, who received fluoxetine averaged amplitude of 2,661 ± 0,5850 mV²/Hz x 10-3, proving fluoxetine efficacy in controlling depression caused by forced swimming. For the group received dexamethasone chronically and fluoxetine to reverse the power of the middle frame was 0.4758 ± 0.2514 mV²/Hz x 10-3, as there is no statistical difference between the dexamethasone group and dexamethasone fluoxetine, fluoxetine failed to reverse depressive symptoms caused by dexamethasone. In the forced swimming, the fluoxetine group had decreased fluctuation time, mean time of 45.33 ± 23.26 seconds, demonstrating that the group was not depressed. In the group administered with dexamethasone chronic form and assessed the possibility of reversing depressive disorder with fluoxetine immobility time average was 169.8 ± 24.5 seconds indicating that fluoxetine had no effect on the depression caused by chronic application of dexamethasone. We conclude from this study that the glucocorticoid cause changes in electrocorticogram and depression in the forced swimming test (FST). Fluoxetine got no effect on the rats subjected to the FST, after the use of dexamethasone.
Acesso aberto (Open Access)
Efeito do cortisol na produção in vitro de embriões bovinos
(Universidade Federal do Pará, 2014-12-19) ALMEIDA, Nathalia Nogueira da Costa de; MIRANDA, Moysés dos Santos; http://lattes.cnpq.br/3354029928888919; OHASHI, Otávio Mitio; http://lattes.cnpq.br/5547874183666459
The aim of this thesis was to evaluate the effect of cortisol in oocyte maturation and bovine embryo culture. In Chapter 1 we analyzed the distribution and location of glucocorticoid receptor (GR) by immunocytochemistry in oocytes, cumulus cells, embryonic cells 2-4, 8-16 cell, morula and blastocyst, and was also verified the presence of mRNA (qualitative RT-PCR) for GR in the stages. The results showed that the GR is present in all cells analyzed. In order to verify the functionality GR in preimplantation embryo development, translation of mRNA for GR zygotes was silenced in the RNAi technique, and subsequent embryo development was analyzed. The embryonic development decreased (P <0.05) after silencing of GR mRNA. The presence of GR oocyte and the cumulus cells indicates that these cells are sensitive to the use of CG. Given this, in Chapter 2, the effects of different cortisol concentrations during in vitro maturation (IVM) of bovine oocytes and embryonic development, apoptosis rate and gene expression (NRF1, COX, TFAM, GLUT1, FASN and HSP70) were analiyzed. The concentrations of cortisol used were 0.01, 0.1 and 1 mg / mL . There was no statistical difference in the number of cells and cleavage rate, but the concentration of 0.1 mg/ml of cortisol increased the blastocyst rate when compared to the control group (without cortisol in IVM) (41 ± 10 versus 21 ± 1.2; p <0.05, respectively). The rate of apoptosis and gene expression in oocytes, cumulus cells and blastocysts was only assessed at a concentration of 0.1 mg / ml of cortisol. There was no statistical difference in the apoptotic index, and not with respect to gene expression in oocytes and cumulus cells for COX genes, NRF1, HSP70 and FASN (p> 0, 05). Regarding embryonic gene expression, only the measurements relative mRNA FASN, GLUT1 and HSP70 were increased in blastocysts treated with 0.1 g/ml during IVM when compared to embryos of the Control group (p <0.05), the other genes showed no change (p> 0.05). In Chapter 3, we investigated the use of cortisol during in vitro culture (IVC) of bovine embryos. As in Chapter 1 was identified GR in all embryonic stages and when the GR expression was silenced and embryonic development was impaired. Thus, in the experiment three different concentrations (0.01, 0.1 and 1 mg / mL) of cortisol in IVC and embryonic development was evaluated same parameters of Chapter 2. There was no statistical difference in the embryos treated with cortisol in different concentrations when compared to the control for the parameters analyzed (p> 0.05). The concentration of 0.1 mg/ml was chosen to evaluate other parameters of embryo quality. Thus, IVC embryos with or without 0.1 mg/mL of cortisol, were analyzed for apoptosis rate and gene expression, not being statistically significant difference in any of the analyzes (p> 0.05). After these studies conclude that oocytes and embryos are responsive to GC, and the addition of cortisol in IVM improves oocyte competence, but the supplementation of IVC with cortisol may not have influence on embryo development.
Acesso aberto (Open Access)
Fotoperíodo sobre parâmetros fisiológicos relacionados ao estresse em alevinos de tilápia-do-nilo
(2013-10) VERAS, Galileu Crovatto; MURGAS, Luis David Solis; ZANGERONIMO, Márcio Gilberto; ROSA, Priscila Vieira; SOLIS DE LEON, Jonathan Antonio; SALARO, Ana Lúcia
The objective of this study was to evaluate the influence of different photoperiods on physiological parameters related to stress in Nile tilapia fingerlings (Oreochromis niloticus). A completely randomized design with five treatments (0L, 6L, 12L, 18L, 24L) and four replications was used, and the aquarium as the experimental unit. One hundred and sixty tilapia fingerlings, 3.21±0.05g and 4.35±0.07cm were distributed in 20 aquariums of 20L in a recirculation system with temperature controlled at 27 º C and density of eight fish per aquarium. Feeding was performed twice daily with extruded feed containing 40% crude protein, for a period of 75 days. At the end of experimental period, the data of survival, cortisol, glucose and hematocrit were subjected to analysis of variance and, subsequently, in case of significance (P<0.05) a Tukey test 5% was performed to compare means. Manipulation of photoperiod shows no alteration in the homeostasis of juveniles, since there is no difference in survival, blood glucose, hematocrit and plasma cortisol (P>0.05).