ISSN: 2155-9880
Marco A Cordeiro, Luana S Rodrigues, Daniela Ortolani, Ana Elisa TS de Carvalho, Regina C Spadari*
We have previously described that rats submitted to foot shock stress present cardiac β2 -ARs up-regulation and alterations in components of the β2 -AR-Gi signaling pathway related to atrophy. The aim of this work was to investigate the time course of those stress induced alterations in cardiac components of the β2 -AR-Gi signaling pathway related to atrophy. Male rats were submitted to foot shock stress once a day for three consecutive days. Protein expressions were analyzed in the ventricle of rats euthanized immediately, 24 hours or 5 days after the last stress exposure. β2 -ARs were upregulated in the heart of rats sacrificed immediately after stress. However, PI3K, pAkt, and MuRF1 expressions that were lower than control immediately after stress remained lower than control 5 days after stress exposure; atrogin-1 expression was unaltered. It is suggested that MuRF1 and atrogin-1 expressions are independently regulated from each other and that atrophy might be blunted in the heart of stressed rats. Moreover, some intracellular alterations induced by stress are long lasting and remain even after the end of the stress exposure period