Sara Quaglia de Campos Giampá

Resistance training minimizes catabolic effects induced by sleep deprivation in rats

Sleep deprivation (SD) can induce muscle atrophy. We aimed to investigate the changes underpinning SD-induced muscle atrophy and the impact of this condition on rats that were previously submitted to resistance training (RT). Adult male Wistar EPM-1 rats were randomly allocated into 1 of 5 groups: control, sham, SD (for 96 h), RT, and RT+SD. The major outcomes of this study were muscle fiber cross-sectional area (CSA), anabolic and catabolic hormone profiles, and the abundance of select proteins involved in muscle protein synthesis and degradation pathways. SD resulted in muscle atrophy; however, when SD was combined with RT, the reduction in muscle fiber CSA was attenuated. The levels of IGF-1 and testosterone were reduced in SD animals, and the RT+SD group had higher levels of these hormones than the SD group. Corticosterone was increased in the SD group compared with the control group, and this increase was minimized in the RT+SD group. The increases in corticosterone concentrations paralleled changes in the abundance of ubiquitinated proteins and the autophagic proteins LC3 and p62/SQSTM1, suggesting that corticosterone may trigger these changes. SD induced weight loss, but this loss was minimized in the RT+SD group. We conclude that SD induced muscle atrophy, probably because of the increased corticosterone and catabolic signal. High-intensity RT performed before SD was beneficial in containing muscle loss induced by SD. It also minimized the catabolic signal and increased synthetic activity, thereby minimizing the bodys weight loss.

Negative Energy Balance Induced by Paradoxical Sleep Deprivation Causes Multicompartmental Changes in Adipose Tissue and Skeletal Muscle

Objective. Describe multicompartmental changes in the fat and various muscle fiber types, as well as the hormonal profile and metabolic rate induced by SD in rats. Methods. Twenty adult male Wistar rats were equally distributed into two groups: experimental group (EG) and control group (CG). The EG was submitted to SD for 96 h. Blood levels of corticosterone (CORT), total testosterone (TESTO), insulin like growth factor-1 (IGF-1), and thyroid hormones (T3 and T4) were used to assess the catabolic environment. Muscle trophism was measured using a cross-sectional area of various muscles (glycolytic, mixed, and oxidative), and lipolysis was inferred by the weight of fat depots from various locations, such as subcutaneous, retroperitoneal, and epididymal. The metabolic rate was measured using oxygen consumption (V˙O2) measurement. Results. SD increased CORT levels and decreased TESTO, IGF-1, and T4. All fat depots were reduced in weight after SD. Glycolytic and mixed muscles showed atrophy, whereas atrophy was not observed in oxidative muscle. Conclusion. Our data suggest that glycolytic muscle fibers are more sensitive to atrophy than oxidative fibers during SD and that fat depots are reduced regardless of their location.

Iron-Restricted Diet Affects Brain Ferritin Levels, Dopamine Metabolism and Cellular Prion Protein in a Region-Specific Manner

Iron is an essential micronutrient for several physiological functions, including the regulation of dopaminergic neurotransmission. On the other hand, both iron, and dopamine can affect the folding and aggregation of proteins related with neurodegenerative diseases, such as cellular prion protein (PrPC) and α-synuclein, suggesting that deregulation of iron homeostasis and the consequential disturbance of dopamine metabolism can be a risk factor for conformational diseases. These proteins, in turn, are known to participate in the regulation of iron and dopamine metabolism. In this study, we evaluated the effects of dietary iron restriction on brain ferritin levels, dopamine metabolism, and the expression levels of PrPC and α-synuclein. To achieve this goal, C57BL/6 mice were fed with iron restricted diet (IR) or with normal diet (CTL) for 1 month. IR reduced iron and ferritin levels in liver. Ferritin reduction was also observed in the hippocampus. However, in the striatum of IR group, ferritin level was increased, suggesting that under iron-deficient condition, each brain area might acquire distinct capacity to store iron. Increased lipid peroxidation was observed only in hippocampus of IR group, where ferritin level was reduced. IR also generated discrete results regarding dopamine metabolism of distinct brain regions: in striatum, the level of dopamine metabolites (DOPAC and HVA) was reduced; in prefrontal cortex, only HVA was increased along with the enhanced MAO-A activity; in hippocampus, no alterations were observed. PrPC levels were increased only in the striatum of IR group, where ferritin level was also increased. PrPC is known to play roles in iron uptake. Thus, the increase of PrPC in striatum of IR group might be related to the increased ferritin level. α-synuclein was not altered in any regions. Abnormal accumulation of ferritin, increased MAO-A activity or lipid peroxidation are molecular features observed in several neurological disorders. Our findings show that nutritional iron deficiency produces these molecular alterations in a region-specific manner and provide new insight into the variety of molecular pathways that can lead to distinct neurological symptoms upon iron deficiency. Thus, adequate iron supplementation is essential for brain health and prevention of neurological diseases.

Paradoxical Sleep Deprivation Causes Cardiac Dysfunction and the Impairment Is Attenuated by Resistance Training

Background Paradoxical sleep deprivation activates the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, subsequently interfering with the cardiovascular system. The beneficial effects of resistance training are related to hemodynamic, metabolic and hormonal homeostasis. We hypothesized that resistance training can prevent the cardiac remodeling and dysfunction caused by paradoxical sleep deprivation. Methods Male Wistar rats were distributed into four groups: control (C), resistance training (RT), paradoxical sleep deprivation for 96 hours (PSD96) and both resistance training and sleep deprivation (RT/PSD96). Doppler echocardiograms, hemodynamics measurements, cardiac histomorphometry, hormonal profile and molecular analysis were evaluated. Results Compared to the C group, PSD96 group had a higher left ventricular systolic pressure, heart rate and left atrium index. In contrast, the left ventricle systolic area and the left ventricle cavity diameter were reduced in the PSD96 group. Hypertrophy and fibrosis were also observed. Along with these alterations, reduced levels of serum testosterone and insulin-like growth factor-1 (IGF-1), as well as increased corticosterone and angiotensin II, were observed in the PSD96 group. Prophylactic resistance training attenuated most of these changes, except angiotensin II, fibrosis, heart rate and concentric remodeling of left ventricle, confirmed by the increased of NFATc3 and GATA-4, proteins involved in the pathologic cardiac hypertrophy pathway. Conclusions Resistance training effectively attenuates cardiac dysfunction and hormonal imbalance induced by paradoxical sleep deprivation.

Effect Of Resistance Training On Myocardial Contractility In Vitro After Sleep Deprivation

Fundamento: O treinamento resistido promove beneficios a saude cardiovascular, a qual e influenciada pela privacao de sono. Objetivo: Investigar o efeito previo do treinamento resistido de alta intensidade sobre a contratilidade miocardica de ratos privados de sono paradoxal. Metodos: Quarenta ratos machos Wistar foram distribuidos nos grupos controle (CTRL), treinamento resistido (TRES), privacao de sono paradoxal por 96 horas (PSP96) e treinamento resistido seguido de privacao de sono paradoxal por 96 horas (TRES/PSP96). O treinamento resistido foi de alta intensidade, por 8 semanas, 5x/semana. Vinte e quatro horas apos a ultima sessao de treinamento, os grupos PSP96 e TRES/PSP96 foram submetidos ao protocolo de privacao de sono paradoxal e em seguida foi realizado o estudo in vitro da mecânica contratil do musculo papilar isolado. Resultados: Em comparacao ao CTRL, os grupos PSP96 e TRES/PSP96 apresentaram menor comprimento do musculo papilar e aumento da area de seccao transversa. Associado a essas alteracoes, verificou-se a diminuicao das derivadas temporais da forca na contracao e relaxamento em todas as condicoes avaliadas. Somente o grupo PSP96 apresentou reducao da tensao de repouso e lentidao no tempo de relaxamento, sendo este ultimo atenuado pelo treinamento resistido previo. Conclusao: O treinamento resistido previo a PSP foi parcialmente protetor contra as alteracoes contrateis do musculo papilar, minimizando a lentidao no tempo de relaxamento. Assim, o carater de alta intensidade do protocolo adotado parece nao proteger plenamente o tecido cardiaco frente a PSP.

Exercise performed at hypoxia influences mood state and anxiety symptoms

During hypoxia conditions, psychological states can be worsened. However, little information is available regarding the effect of physical exercise performed in hypoxia conditions on mood state and anxiety symptoms. The aim of the present study was to elucidate the acute effect of moderate physical exercise performed at hypoxia on mood states and anxiety symptoms in healthy young subjects. Ten volunteers were subjected to the following conditions: a normoxic condition (NC) and a hypoxic condition (HC). They performed 45 min of physical exercise. Their anxiety symptoms and mood states were evaluated at the initial time point as well as immediately following and 30 and 60 min after the exercise session. Our results showed a significant increase in post-exercise anxiety symptoms and a significant decrease in mood scores immediately after and 30 min after exercise performed in the HC. Moderate physical activity performed at hypoxia condition increased post-exercise anxiety and worsened mood state.

El ejercicio realizado en la hipoxia influencias estado de ánimo y síntomas de ansiedad

During hypoxia conditions, psychological states can be worsened. However, little information is available regarding the effect of physical exercise performed in hypoxia conditions on mood state and anxiety symptoms. The aim of the present study was to elucidate the acute effect of moderate physical exercise performed at hypoxia on mood states and anxiety symptoms in healthy young subjects. Ten volunteers were subjected to the following conditions: a normoxic condition (NC) and a hypoxic condition (HC). They performed 45 min of physical exercise. Their anxiety symptoms and mood states were evaluated at the initial time point as well as immediately following and 30 and 60 min after the exercise session. Our results showed a significant increase in post-exercise anxiety symptoms and a significant decrease in mood scores immediately after and 30 min after exercise performed in the HC. Moderate physical activity performed at hypoxia condition increased post-exercise anxiety and worsened mood state.

Exercício realizado em hipóxia influencia o estado de humor e sintomas de ansiedade

During hypoxia conditions, psychological states can be worsened. However, little information is available regarding the effect of physical exercise performed in hypoxia conditions on mood state and anxiety symptoms. The aim of the present study was to elucidate the acute effect of moderate physical exercise performed at hypoxia on mood states and anxiety symptoms in healthy young subjects. Ten volunteers were subjected to the following conditions: a normoxic condition (NC) and a hypoxic condition (HC). They performed 45 min of physical exercise. Their anxiety symptoms and mood states were evaluated at the initial time point as well as immediately following and 30 and 60 min after the exercise session. Our results showed a significant increase in post-exercise anxiety symptoms and a significant decrease in mood scores immediately after and 30 min after exercise performed in the HC. Moderate physical activity performed at hypoxia condition increased post-exercise anxiety and worsened mood state.