Transcapillary PO₂ Gradients in Contracting Muscle of Rat Model of Sepsis

This study aimed to evaluate the effect of cecal ligation and puncture (CLP)-induced sepsis on transcapillary PO₂ gradients (ΔPO₂) in contracting skeletal muscles.

Male Wistar rats (n = 16, 10 weeks old) were randomly assigned to sham or CLP groups. Seven days after surgery, microvascular (PO₂mv) and interstitial (PO₂is) PO₂ levels in the tibialis anterior muscle were measured using the phosphorescence quenching method during the transition from rest to electrically induced muscle contractions. ΔPO₂ was calculated as PO₂mv minus PO₂is.

At rest, there were no differences in PO₂mv, PO₂is, and ΔPO₂ between the sham and CLP groups. The PO₂mv and PO₂is decreased during the transition from rest to contractions in both groups. During muscle contractions, the PO₂mv and ΔPO₂ were significantly lower in the CLP group than in the sham group (PO₂mv, 7.79 ± 5.03 vs. 4.43 ± 2.23; ΔPO₂, 5.50 ± 4.46 vs. 1.82 ± 2.66 mm Hg; sham vs. CLP; p < 0.05). The ΔPO₂ of the rats in the sham group remained unchanged; however, it markedly decreased during muscle contractions in the CLP group.

Sepsis reduced ΔPO₂ in contracting skeletal muscles.