Navegando por Palavras-chave "body temperature"
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- 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.
- ItemSomente MetadadadosRole of preoptic second messenger systems (cAMP and cGMP) in the febrile response(Elsevier B.V., 2002-07-19) Steiner, A. A.; Antunes-Rodrigues, J.; Branco, LGS; Universidade Federal de São Paulo (UNIFESP); Dent Sch Ribeirao PretoThe present study aimed to test the hypothesis that a decrease in preoptic cAMP mediates fever. To this end, body core temperature (T-c) of unanesthetized, freely moving rats was monitored by biotelemetry before and after pharmacological modulation of the cAMP pathway, and cAMP levels in the anteroventral third ventricular region (AV3V), where the preoptic region (POA) is located, were determined. We observed that intra-POA administration of the cAMP agonist dibutyryl-cAMP (Db-cAMP, 40 mug) reduced T-c. PGE(2) (the proximal mediator of fever, 200 ng) raised T-c with a concomitant decrease in AV3V cAMP levels from 22.7+/-1.8 to 17.0+/-1.0 fmol/mug protein. Moreover, PGE(2)-induced fever was impaired by the phosphodiesterase inhibitor aminophylline. in order to verify the interaction between the cAMP- and cGMP-dependent pathways in the POA, we then co-injected Db-cAMP and 8-Br-cGMP into the POA. As a result, 8-Br-cGMP augmented the drop in 7 evoked by Db-cAMP. Lastly, we observed that intra-POA co-microinjection of the protein kinase A inhibitor (Rp-cAMPS, 1 mug) with the protein kinase G inhibitor (Rp-cGMPS, 1 mug), mimicking the effects of reduced production of cAMP and cGMP, respectively, produced a fever-like response. in summary, the present data support that a decrease in the levels of cAMP and cGMP in the POA is associated with the genesis of fever. (C) 2002 Elsevier Science BY. All rights reserved.
- ItemAcesso aberto (Open Access)VARIATION OF EXPLOSIVE FORCE AT DIFFERENT TIMES OF DAY(Inst Sport, 2011-01-01) Pereira, R.; Machado, M.; Ribeiro, W.; Russo, Adriana Kowalesky [UNIFESP]; Paula, A. de; Lazo-Osorio, R. A.; UESB; Univ Vale Paraiba UNIVAP; Univ Iguacu; Univ Fdn Itaperuna FUNITA; Universidade Federal de São Paulo (UNIFESP)AIM: The purpose of this study was to compare the explosive force and electromyographic (EMG) activity at three different times of the day. METHODS: Thirty healthy subjects took part in the study, and carried out two maximum isometric voluntary knee extensions to measure explosive force, through contractile impulse (Cl) and rate of force development (RFD), and myoelectric signals from quadriceps muscles in the following periods: 07:30-09:30, 13:30-15:30 and 19:30-21:30 (called morning, afternoon and night respectively), on three non-consecutive days. RESULTS: The body temperature was lower in the morning than in the afternoon and night periods. The explosive force, evaluated through contractile impulse (Cl) and rate of force development (RFD), was greater at night than in the morning, without differences in the myoelectric signal. CONCLUSION: The ability to produce explosive force varies throughout different times of the day without variation in muscular recruitment, indicating that peripheral and not neural mechanisms could be responsible for this variation.