Alterações autonômicas e renais na prole masculina de ratas restritas de sono durante final da prenhez
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Data
2015-04-30
Autores
Raimundo, Joyce Regina Santos [UNIFESP]
Orientadores
Gomes, Guiomar Nascimento Gomes [UNIFESP]
Tipo
Dissertação de mestrado
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Resumo
A restrição de sono está associada a diversas alterações tais como: hipertensão arterial sistêmica, diminuição do controle glicêmico e obesidade. Considerando-se que modificações no ambiente materno podem resultar em alterações na prole, o objetivo do presente trabalho é estudar o impacto da restrição do sono durante a prenhez sobre a morfologia e função renal e função cardiovascular dos filhotes em idade adulta. Avaliamos a morfologia renal, função renal, função do barorreflexo cardíaco, tônus autonômico e balanço simpato-vagal para o coração e a pressão arterial na prole do sexo masculino. Para o estudo, fêmeas Wistar, com 3 meses de idade foram colocadas para cruzar. Após a confirmação da prenhez, estas foram divididas em dois grupos experimentais: C (controle) e RS (restrição de sono entre o 14º e o 20º dia de prenhez). A restrição de sono foi realizada pelo método da plataforma múltipla, por 20 horas diárias. Após o nascimento, foram selecionados 6 filhotes por mãe(preferencialmente na proporção de 4 machos para 2 fêmeas), designados como FMC (filhos de mães C) e FMRS (filhos de mães RS); as fêmeas não foram utilizadas neste estudo. Na primeira parte deste estudo a pressão arterial indireta (PA) foi aferida por pletismografia aos 3 meses, e a seguir foram avaliados os seguintes parâmetros de função renal: ritmo de filtração glomerular (RFG), fluxo plasmático renal (FPR), área glomerular, cargas excretas e filtradas de sódio e potássio, excreção renal de ácidos, osmolaridade urinária e fluxo urinário. Após a avaliação funcional os rins foram retirados para análise morfológica. Em relação ao grupo controle, observamos em FMRS aumento do RFG (9.2 ± 0.4 versus 7.9 ± 0.2 mL/min/Kg) e aumento da área glomerular (8125 ± 156.9 versus 7693 ± 135.6 um2). Na segunda parte do estudo foram adquiridos parâmetros cardiovasculares diretos e foi avaliada sensibilidade barorreflexa cardíaca, tônus autonômico e balanço simpato-vagal, em outro grupo de animais ao 4 meses. Em relação ao grupo controle, observamos em FMRS diminuição do barorreflexo cardíaco (-1.59 ± 0.12 versus -2.21 ± 0.12 bpm/mmHg), aumento do tônus simpático para o coração (-40.08 ± 8.81 versus -14.76 ± 3.27 bpm) e desbalanço simpato-vagal (0.38 ± 0.043 versus 0.17 ± 0.014 Hz). Estes resultados sugerem que o aumento da pressão arterial esteja associado às alterações encontradas na morfologia e na função glomerular do grupo FMRS. O aumento do tônus simpático para o coração e diminuição no controle barorreflexo cardíaco observados em FMRS sugerem que alterações centrais estejam envolvidas no aumento da pressão arterial.
The sleep restriction is related with several disorders such as: hypertension, decreased glycemic control and obesity. Considering that changes in maternal environment may result in changes in the offspring, the aim of this work was to study the impact of sleep restriction during pregnancy on renal morphology and function and on cardiovascular function of the offspring at adult age. Renal morphology and function were evaluated in male offspring at 3 months old. The cardiac baroreflex function, autonomic tonus and sympatho-vagal balance to the heart were evaluated at 4 months old. For this study, female rats at 3 months old were placed for matting. After confirmation of pregnancy, the rats were divided into two experimental groups: C (control) and RS (submitted to sleep restriction between the 14th and 20th day of pregnancy). The sleep restriction was performed by the method of multi-platform, for 20 hours daily. After birth, 6 offspring were selected from each mother (preferably at a ratio of 4 males to 2 females) and designated as FMC (offspring from C mothers) and FMRS (offspring from SR mothers), females offspring were not used in this study. In the first part of this study blood pressure (BP) was measured by plethysmography at 3 months, and then, the following parameters of renal function were assessed: glomerular filtration rate (GFR), renal plasma flow (RPF), glomerular area, filtered and excreted load of sodium and potassium, renal excretion of acids, urinary flow and urinary osmolarity. After functional evaluation kidneys were withdrawn to morphological analysis. In comparison to FMC, we observed in FMRS group an increase in GFR (9.2 ± 0.4 versus 7.9 ± 0.2 mL/min/Kg), and in glomerular area (8125 ± 156.9 versus 7693 ± 135.6 um2). In the second part of this study direct cardiovascular parameters were measured and baroreflex sensitivity, autonomic tonus and sympatho-vagal balance to the heart were evaluated in other groups at 4 month age. In comparison to FMC, we observed in FMRS group a decreased in cardic baroreflex (-1.59 ± 0.12 versus -2.21 ± 0.12 bpm/mmHg), increased sympathetic tone to the heart (-40.08 ± 8.81 versus -14.76 ± 3.27 bpm) and an imbalance sympatho-vagal (0.38 ± 0.043 versus 0.17 ± 0.014 Hz). These results suggest that the elevation of arterial pressure is associated with alterations found in renal morphology and function at FMRS group. The increased sympathetic tone to the heart and decrease in cardiac baroreflex control observed in FMRS suggest that central changes are involved in the elevation of arterial pressure.
The sleep restriction is related with several disorders such as: hypertension, decreased glycemic control and obesity. Considering that changes in maternal environment may result in changes in the offspring, the aim of this work was to study the impact of sleep restriction during pregnancy on renal morphology and function and on cardiovascular function of the offspring at adult age. Renal morphology and function were evaluated in male offspring at 3 months old. The cardiac baroreflex function, autonomic tonus and sympatho-vagal balance to the heart were evaluated at 4 months old. For this study, female rats at 3 months old were placed for matting. After confirmation of pregnancy, the rats were divided into two experimental groups: C (control) and RS (submitted to sleep restriction between the 14th and 20th day of pregnancy). The sleep restriction was performed by the method of multi-platform, for 20 hours daily. After birth, 6 offspring were selected from each mother (preferably at a ratio of 4 males to 2 females) and designated as FMC (offspring from C mothers) and FMRS (offspring from SR mothers), females offspring were not used in this study. In the first part of this study blood pressure (BP) was measured by plethysmography at 3 months, and then, the following parameters of renal function were assessed: glomerular filtration rate (GFR), renal plasma flow (RPF), glomerular area, filtered and excreted load of sodium and potassium, renal excretion of acids, urinary flow and urinary osmolarity. After functional evaluation kidneys were withdrawn to morphological analysis. In comparison to FMC, we observed in FMRS group an increase in GFR (9.2 ± 0.4 versus 7.9 ± 0.2 mL/min/Kg), and in glomerular area (8125 ± 156.9 versus 7693 ± 135.6 um2). In the second part of this study direct cardiovascular parameters were measured and baroreflex sensitivity, autonomic tonus and sympatho-vagal balance to the heart were evaluated in other groups at 4 month age. In comparison to FMC, we observed in FMRS group a decreased in cardic baroreflex (-1.59 ± 0.12 versus -2.21 ± 0.12 bpm/mmHg), increased sympathetic tone to the heart (-40.08 ± 8.81 versus -14.76 ± 3.27 bpm) and an imbalance sympatho-vagal (0.38 ± 0.043 versus 0.17 ± 0.014 Hz). These results suggest that the elevation of arterial pressure is associated with alterations found in renal morphology and function at FMRS group. The increased sympathetic tone to the heart and decrease in cardiac baroreflex control observed in FMRS suggest that central changes are involved in the elevation of arterial pressure.
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Citação
RAIMUNDO, Joyce Regina Santos. Alterações autonômicas e renais na prole masculina de ratas restritas de sono durante final da prenhez. 2015. 89 f. Dissertação (Mestrado em Farmacologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.