The effect of sepsis and reactive oxygen species on skeletal muscle interstitial oxygen pressure during contractions

This study aims to examine the effect of sepsis on the dynamics of skeletal muscle partial oxygen pressure during muscle contractions as well as the effect of reactive oxygen species (ROS) scavenger (ascorbic acid, Asc).

Twenty-seven male Sprague-Dawley rats (2-3 months old) were randomly assigned to three groups; sham, cecal ligation and puncture (CLP), or CLP plus ascorbic acid treatment group (CLP + Asc). Electrical stimuli-induced muscle contractions and partial oxygen pressure measurements were performed at 3 h after CLP. The interstitial oxygen pressure (PO₂ is) in the spinotrapezius muscle was measured by the phosphorescence quenching method.

The PO₂ is at rest was not different between the three groups. The PO₂ is decreased from rest to contraction in all groups. Compared to the sham, the time to decrease PO₂ is was significantly faster in CLP but not in CLP + Asc (p < .05). Compared to the sham, the PO₂ is during muscle contractions was significantly lower in both CLP and CLP + Asc (p < .05, respectively).

Our results suggest that CLP-induced sepsis accelerated the decay of PO₂ is at the onset of muscle contractions and maintained a low level of PO₂ is during muscle contractions.