Análise metabólica em ratos Wistar submetidos à dessincronização circadiana forçada e alimentação em tempo restrito

• Main Author: Oliveira, Isis Gabrielli Barbieri de
• Publication Date: 2023
• Format: Doctoral thesis
• Language: por
• Source: Repositório Institucional da UFG
• Download full: http://repositorio.bc.ufg.br/tede/handle/tede/12756
• topic: Desalinhamento circadiano; Alimentação em tempo restrito; Metabolismo; Cronobiologia; Sistema antioxidante; Circadian misaligment; Time restricted feeding; Metabolism; Chronobiology; Antioxidant system; CIENCIAS BIOLOGICAS

The suprachiasmatic nucleus is part of a multi-oscillatory timing system in mammals, regulating various physiological rhythms and under modulation by internal or environmental synchronizers, among them: the light-dark cycle (LD), the most important photic synchronizer of this system. However, non-photic synchronizers such as food availability remain more unclear. Here, we use Wistar rats (250-300g) randomly distributed into four groups: control CTR AL under a symmetrical cycle of 12:12h LD and ad libitum food availability or CTR RF with time-restricted feeding (TRF); DSC AL submitted to the forced circadian desynchronization protocol under a symmetrical cycle of 11:11h LD with ad libitum food availability and DSC RF with TRF, during eight weeks to evaluate the impact of DSC and TRF on locomotor activity, hepatic metabolism and on the antioxidant system. During the eighth week, all animals were submitted to the insulin and glucose tolerance test – ipITT and oGTT. After 48h of recovery, they were euthanized. Plasma, liver and hypothalamus samples were removed and stored for biochemical analyses, Western blotting and RT-qPCR. Results: As expected, all DSC animals showed dissociation of the locomotor activity rhythm. TRF increased the rate of dyssynchrony in the DSC RF group, indicating dominance of the light-entrained component (LEC). DSC or TRF separately did not alter total food intake or body mass, but the association of both included total food intake, reflecting on the evolution of body mass. However, the separate analysis of food intake in the LD phases demonstrates that in the light phase intake is higher in the DSC group when compared to the CTR AL.TRF promotes simultaneous increase of NPY and CART only in animals under LD cycle 12:12h. DSC increased DSC increased the gene expression of PTEN, PTPN1 and G6Pase, the PI3K protein, the activity of SOD-1 and catalase enzymes and the oxidative stress biomarkers TBARS and protein carbonyl in the liver, but TRF attenuated only the effects on G6Pase and PI3K. Conclusion: In summary, these findings show that forced desynchronization increases considerable oxidative stress and promotes changes in insulin signaling in liver, which were not attenuated by the association with TRF