Changes in the cardiac phosphotransfer network associated with oxidative stress in experimentally infected Brucella ovis mice

The aim of this study was to evaluate whether Brucella ovis infection altered the activities of cardiac enzymes belonging to the phosphotransfer network and cause an oxidative imbalance in mice, used as an experimental model. We used hearts from 48 mice in two groups (n = 24 each): uninfected (control group) and infected by B. ovis, collected on days 7, 15, 30, and 60 post-infection (PI). Cardiac cytosolic creatine kinase (CK) activity was higher in infected animals than in the control group on days 30 and 60 PI, while cardiac mitochondrial CK activity was lower at the same moments of infection. Cardiac pyruvate kinase (PK) activity was lower in infected animals than in the control group on day 60 PI, while no significant difference was observed between groups regarding cardiac adenylate kinase (AK) activity. Cardiac thiobarbituric acid reactive substances (TBARS) were higher in infected animals than in the control group on days 30 and 60 PI, while non-protein thiol (NPSH) levels were lower on days 30 and 60 PI. Finally, cardiac SOD activity was higher in infected animals than in the control group on day 60 PI. The inhibition on mitochondrial CK activity caused an impairment of cardiac energy homeostasis, possibly through depletion of ATP production, although cytosolic cardiac CK activity acted in an attempt to restore the mitochondrial ATP levels through a feedback mechanism.