Estudo da termorregulação em ratos espontaneamente hipertensos submetidos aos exercícios físicos progressivo e contínuo até a fadiga em ambiente quente

• Autor(a) principal: Campos, Helton Oliveira
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3490
• topic: Termorregulação; Ratos; Hipertensão; Thermoregulation; Mouse; Hypertension; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

The hypothesis of this study was that during progressive exercise until fatigue (PEF) and continuous exercise until fatigue (CEF) in a hot enviroment (HE) the spontaneously hypertensive rats (SHR) would present thermoregulatory déficits in relation to theirs normotensives controls. The objective was to study thermoregulation in SHR submitted to the PEF and CEF in HE. For that were measured the core body temperature (Tcore), the tail skin temperature (Tskin), the oxigen cosumption (VO2) and time to fatigue (TTE) in Wistar rats (n=8) and SHR (n=8) for four experimental conditions: (1) progressive exercise until fatigue in a hot enviroment (PEF-HE), (2) progressive exercise until fatigue in a temperate enviroment (PEF-HE), (3) continuous exercise until fatigue in a hot enviroment (CEF-HE) and (4) continuous exercise until fatigue in a temperate enviroment (CEF-HE). The temperature of the treadmill to the temperate enviroment (TE) e HE was fixed at 25 and 32°C, respectively. The Kolmogorov-Sminorf was used to test the normality of the data. Differences between groups were analyzed using two-way ANOVA followed by Tukey post-hoc, if necessary. To evaluate the values of Tcore, Tskin and VO2 during the experiments at baseline and fatigue, we used the Student t test. Data are presented as mean ± SEM, The level of significance adopted was until 5%. In PEF, the SHR-TE had higher VO2 than group WIS-TE, however the SHR-TE also showed higher Tskin than in group WIS-TE. Thus, there was a thermal equilibrium wich resulted in Tcore similar between groups in PEF. In the CEF, the SHR-HE showed higher Tcore compared to WIS-HE group. Moreover, there were no differences in Tskin and VO2 between groups. When the exercise was conducted in the HE the TTE was reduced compared to TE. It was shown that during the EPF-AT SHR had higher production and heat dissipation in the final moments of the year in relation to the controls, so the Tint was similar between SHR and WIS. During the ECF-AQ animals Tcore SHR had higher than their controls at the very end of the year, despite having dissipation and heat production similar to their controls.