In sepsis, greater understanding of the inflammatory mechanism involved would provide insights into the condition and into its extension to the muscular apparatus in critically ill patients. Therefore, this study evaluates the inflammatory profile of pneumosepsis induced by Klebsiella pneumoniae (K.p.) in lungs and skeletal muscles during the first 72 h. Male BALB/c mice were divided into 4 groups, submitted to intratracheal inoculation of K.p. at a concentration of 2 × 108 (PS) or PBS, and assessed after 24 (PS24), 48 (PS48) and 72 (PS72) hours. The Maximum Physical Capacity Test (MPCT) was performed before and after induction. Pulmonary inflammation was assessed by total cell number, nitric oxide levels (NOx), IL-1β and TNF-α levels in bronchoalveolar lavage fluid (BALF); inflammation and muscle trophism were evaluated by the levels of TNF-α, IL-6, TGF-β and BDNF by ELISA and NF-κB by western blotting in muscle tissue. Cells and colony forming units (CFU) were also analyzed in blood samples. The PS groups showed an increase in total cells in the BALF (p < 0.05), as well in the number of granulocytes in the blood (p < 0.05) and a decrease in performance in the MPCT (p < 0.05). NOx levels showed significant increase in PS72, when compared to Control group (p = 0.03). The PS24 showed a significant increase lung in TNF-α levels (p < 0.001) and in CFU (p = 0.013). We observed an increase in muscular IL-6 and nuclear NF-κB levels in PS24 group, when compared to PS48 and Control groups (p < 0.05). Nevertheless, mild signs of injury in the skeletal muscle tissue does not support the idea of an early muscular injury in this experimental model, suggesting that the low performance of the animals during the MPCT may be related to lung inflammation.
Keywords: IL-6; Muscle injury; NF-κB; Pulmonary inflammation; Sepsis.
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