Hipertensão induzida pela dexametasona é atenuada pelo pré-condicionamento físico sem a participação do sistema renina angiotensina

• Autor(a) principal: Prazeres, Paula Bessi Constantino [UNESP]
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155508; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-05-25/000885226.pdf
• topic: Glicocorticoides; Pressão arterial; Angiotensina II; Exercícios físicos

Dexamethasone (DEX) is widely used to treat inflammation and allergies, but its chronic use determines several side effects such as hyperglycemia, muscle atrophy and hypertension (H). The renin-angiotensin system (RAS) is an important regulator of blood pressure (BP) and its increased activity may be one possible mechanism responsible to increase BP induced by DEX. On the other hand, low to moderate aerobic exercise has been recommended for treatment of hypertension and its effects on RAS have been demonstrated. Previous work demonstrated that physical preconditioning attenuates H induced by DEX, however little is known about the mechanisms responsible for this response. Therefore, the aim of this study was to investigate whether RAS and/or baroreflex participated in the BP increase induced by DEX and BP reduction induced by aerobic preconditioning was associated with an alteration of RAS components and/or baroreflex. Rats were subjected to an aerobic exercise protocol on the treadmill or kept sedentary for 8 weeks. Additionally, animals were treated with DEX (1.0mg/kg of body weight per day i.p. for 10 days). Groups were: sedentary control (SC), DEX sedentary (SD), trained control (TC) and trained DEX (TD). Body weight (BW), fasting glucose, resting blood pressure and baroreflex activity were analyzed. After euthanasia, the tibialis anterior (TA), soleus (SOL), flexor hallucis longus (FHL) and left ventricle (LV) were collected for evaluation protein levels of RAS components. Treatment with DEX caused decrease of BW and TA and FHL muscle weight (MW), and determined an increase in fasting glucose (+132%) and BP (+16%). Physical training did not prevent BW or MW loss, however it attenuated the increase in fasting glucose (-60%) and BP (-7%). Training increased 31% (TC) and 47% (TD) the protein levels of AGT in the LV muscle. In the TA muscle, DEX also reduced AT2 (-5%) protein levels and training...