ABSTRACT
NEW FINDINGS: What is the central question of this study? What are the effects of different periods of REM sleep restriction (7, 14 and 21 days) on metabolic parameters in young rats? What is the main finding and its importance? Animals submitted to each period of REM sleep deprivation showed a negative energy balance, with reduced body weight gain, body energy gain and gross food efficiency, less body fat content, and increased energy expenditure. There was no increase in food intake after any of the REM sleep restriction periods. In young rats, negative energy balance is not compensated by increased dietary intake as observed in adult rats. ABSTRACT: Reduced sleep is associated with metabolic alterations, not only in adults, but also in children and adolescents. Several studies have shown that sleep restricted (SR) adult rats exhibit metabolic changes, followed by increased food intake, but few have evaluated these functions in young animals. The aim of the present study was to establish the metabolic parameters of young rats subjected to different periods of REM sleep restriction and to propose a correction factor for the correct measurement of food intake. Young male Wistar rats were distributed in control and SR groups for 7, 14 or 21 days. Sleep restriction was performed by the single platform method for 18 h. Regardless of the length of sleep restriction, all SR rats had a negative energy balance, evidenced by reduction in body weight gain, body energy gain and gross food efficiency, accompanied by increased energy expenditure. In addition, sleep restriction reduced body fat content throughout the entire period. Discounting food spillage, there was no increase in food intake by SR rats. In conclusion, the present study revealed metabolic changes in SR young rats after different lengths of REM sleep restriction and that weight loss and increased energy expenditure were not compensated by increased dietary intake as occurs in adult rats, indicating that young rats use other mechanisms to cope with the negative energy balance caused by sleep restriction. In addition, we propose a correction factor for food intake, to prevent overestimation of this parameter, due to food spillage in the water containers.
Subject(s)
Energy Metabolism , Feeding Behavior , Sleep Deprivation , Animals , Eating , Male , Rats , Rats, Wistar , Weight LossABSTRACT
O objetivo do trabalho foi avaliar o processo de transporte rodoviário de bovinos abatidos em um abatedouro-frigorífico da cidade de Uberlândia-MG. Foi avaliado o processo de manejo, embarque e transporte de 502 bovinos encaminhados para o abate e oriundos de 10 propriedades rurais. Falhas no manejo ocorreram em 80% das propriedades avaliadas, já problemas nas instalações chegaram a 60% das propriedades sendo que a má qualidade do embarcador foi o principal motivo de levar animais a quedas no embarque. Apesar do processo de transporte parecer simples, observou-se presença de várias falhas na propriedade, embarque e no transporte até a chegada ao abatedouro, podendo ocasionar aumento do estresse animal e perdas econômicas.
Subject(s)
Animals , Cattle , Red Meat/analysis , Abattoirs , Products Transport , Animal WelfareABSTRACT
Studies have shown a gradual reduction of sleep time in the general population, accompanied by increased food intake, representing a risk for developing obesity, type II diabetes and cardiovascular disease. Rats subjected to paradoxical sleep deprivation (PSD) exhibit feeding and metabolic alterations, both of which are regulated by the communication between peripheral signals and the hypothalamus. This study aimed to investigate the daily change of 96 h of PSD-induced food intake, body weight, blood glucose, plasma insulin and leptin concentrations and the expression of their receptors in the hypothalamus of Wistar rats. Food intake was assessed during the light and dark phases and was progressively increased in sleep-deprived animals, during the light phase. PSD produced body weight loss, particularly on the first day, and decreased plasma insulin and leptin levels, without change in blood glucose levels. Reduced leptin levels were compensated by increased expression of leptin receptors in the hypothalamus, whereas no compensations occurred in insulin receptors. The present results on body weight loss and increased food intake replicate previous studies from our group. The fact that reduced insulin levels did not lead to compensatory changes in hypothalamic insulin receptors, suggests that this hormone may be, at least in part, responsible for PSD-induced dysregulation in energy metabolism.
