Navegando por Palavras-chave "thermoregulation"
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- ItemAcesso aberto (Open Access)Hemodynamic and thermoregulatory effects of xylazine-ketamine mixture persist even after the anesthetic stage in rats(Universidade Federal de Minas Gerais, Escola de Veterinária, 2012-08-01) Picollo, Camila [UNIFESP]; Serra, Andrey Jorge [UNIFESP]; Levy, Rozeli Ferreira [UNIFESP]; Antonio, Ednei Luiz [UNIFESP]; Santos, Leonardo dos [UNIFESP]; Tucci, Paulo José Ferreira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Nove de Julho; Universidade Federal do Espírito SantoThe xylazine-ketamine mixture (KX) is an anesthetic approach commonly administered to assess cardiovascular function in rodents. This study aimed to examine if the cardiovascular and thermoregulatory effects of KX could persist after the anesthetic state ceased in rats. Male Wistar rats were anesthetized with K (50mg/kg) X (10mg/kg) through the intra-peritoneal route. Hemodynamic and thermoregulatory repercussions were evaluated in animals in awake state, during an anesthetic depth and after complete recovery of anesthetized state. KX was efficient to significantly induce deep anesthesia in all rats after 10min. A complete recovery of anesthetized state was observed only after 210min. Compared with preanesthetic state and control animals that received no drug, KX induced a significant reduction of systolic and diastolic blood pressure at 10min. Hypotension was more prominent at 150min. The heart rate was also significantly reduced after 10 min of KX and the highest magnitude of bradycardia was observed at 30min. In addition, rectal temperature was markedly decreased at 30min of KX and the higher reduction occurred at 150min. The hemodynamic and thermoregulatory effects of KX were maintained even after complete anesthetic recovery.
- ItemSomente MetadadadosImpact of maternal diabetes mellitus on the thermoregulation of the offspring(Johann Ambrosius Barth Verlag Medizinverlage Heidelberg Gmbh, 2006-11-01) Guimaraes, A. F.; Martins, C. M. G.; Luz, J.; Universidade Federal de São Paulo (UNIFESP)Maternal diabetes mellitus (DM) can induce metabolic alterations in both newborn and adult offspring. It is believed that inadequate intrauterine conditions can impair thermogenic capacity of the offspring. the objective of the present study was to evaluate the effects of maternal DM on the offspring thermoregulation. DM was induced by streptozotocin injection (60 mg/g) in Wistar EPM-1 female rats. Control animals were injected with an equal volume of citrate buffer solution (pH 4.5). Fifteen days after confirmation of diabetes by glycaemia higher than 250 mg/dl, the rats were mated and the intercourse was confirmed by vaginal smear. Diabetic animals received daily 1 UI of insulin and control animals, an equivalent volume of saline. After delivery, 6 newborn females were randomly assigned to each mother in order to assure equivalent nutritional status during lactation during which body weight of the offspring was recorded daily. At weaning (28th day) the animals were transferred to individual metallic cages kept inside a chamber under a room temperature of 25 degrees C. in the 60th day, half of the offspring was moved to a chamber at 5 degrees C, remaining there until the 90th day. Four experimental groups were thus formed that were the offspring of control or diabetic dams acclimated at 25 degrees C or 5 degrees C. During the whole experimental period body weight and food intake were recorded and during the acclimation period energy balance was determined. When rats were 90 days-old, they were blood sampled and the carcasses prepared for calorimetric de-termination. At birth, weaning and 90 days of age, animals were killed for quantification of body fat, protein and water. Blood samples were collected and used to determine blood glucose and insulin. Offspring from diabetic dams showed lower body weight than controls throughout the whole experiment. No effect of maternal DM on energy balance of offspring acclimated at 25 degrees C or at 5 degrees C was observed. Nevertheless, as expected, cold induced an increase in energy intake and energy expenditure as well as a reduction in food efficiency, which was characterized by lower body weight and fat gain without change in body protein. Body composition was altered only at birth, when animals from diabetic mothers showed decreased body fat content and increased percentage of water in the carcass. Only at 90 days the rats from diabetic mothers showed higher glycaemia and lower blood insulin levels than controls suggesting delayed effects of maternal DM on the offspring. After weaning, rectal temperature of the animals was measured at 25 degrees C and 5 degrees C during 2 hours at time 0, 30, 60, 90, and 120 minutes. This parameter was determined at weaning and at 45, 60, 75, and 90 days of age. the results showed that the offspring from diabetic mothers not only had a delayed thermogenic capacity as shown by their inability to keep body temperature at 5 degrees C until 90 days. It is, thus, suggested that maternal diabetes mellitus delayed thermoregulation of the offspring.
- ItemSomente MetadadadosImpact of maternal food restriction on cold-induced thermogenesis in the offspring(Karger, 2003-01-01) Luz, J.; Griggio, Mauro Antonio [UNIFESP]; Vieira, L. V.; Universidade Federal de São Paulo (UNIFESP)Food restriction imposed during pregnancy usually leads to many alterations in the development of the conceptus. Some of these alterations can be reverted after birth by adequate nutritional rehabilitation, while there are others which are permanent. the aim of this article is to study the influence of maternal food restriction on offspring thermoregulation. Offspring of dams with food restriction during pregnancy (50%) were fed ad libitum after weaning. Rectal temperature was measured every 15 days from weaning to the 90th day of life. From the 60th to the 90th day the animals were either acclimated at 25 or 5degreesC. On the 90th day the animals were killed and their carcasses were processed for energy balance analysis and body composition determination. the results showed that animals from food-restricted mothers were not able to maintain body temperature for a longer period of time than the pups from control dams. Energy balance parameters and body composition did not show significant differences between rats from control and food-restriction mothers at the same environmental temperature. Thus, the results suggest that intrauterine food restriction may delay the development of the hypothalamus-thyroid axis which, in turn, may affect brown adipose tissue development leading to inefficient thermoregulation during neonatal life. Copyright (C) 2003 S. Karger AG, Basel.