Aims: 

Our objectives were to investigate the effects of methane inhalation on macro-and microcirculatory changes in association with the inflammatory processes induced by intestinal ischemia-reperfusion (IR).

Methods: 

Male Sprague-Dawley rats were randomized to control (n=7), IR without methane (IR, n=7) and IR with 2.5% methane added to 21% oxygen (n=7) groups. The superior mesenteric artery (SMA) was occluded for 45 min, which was followed by 120 min reperfusion. Methane treatment was started during the last 10 min of ischemia and lasted for 5 min during reperfusion. Systemic and mesenteric haemodynamics were monitored, the microcirculation of the serosa of the terminal ileum was observed with intravital videomicroscopy (IVM) using orthogonal spectral polarization imaging technique (A/R Cytoscan). The reactive oxygen species (ROS) generation of the reperfused tissues was detected by a chemiluminescence assay, the leukocyte accumulation-specific myeloperoxidase (MPO) activity was assessed by fluorimetry.

Results: 

The significant microcirculatory dysfunction (as evidenced by IVM) after IR was remarkably improved by methane treatment. Moreover, a significantly decreased superoxide production and MPO activity were detected in the methane-treated animals, in contrast with the non-treated IR group.

Conclusion: 

Exogenous methane improves the perfusion deficiency of the mucosa after IR, and this effect may be linked to ROS scavenging or inhibition of leukocyte activation in the reperfused intestinal tissues.

Supported: 

TÁMOP-4.2.2-08/1-2008-0013