Effects of ischaemia-reperfusion injury (I\R) of liver on expression of rat glutathione S-transferase (rGST) isoenzymes that metabolize products of oxidative stress were examined. Rats underwent lobar liver ischaemia for 30 min followed by reperfusion. In ischaemic lobes, rGSTA1\A2 transcript levels increased significantly 12 h after I\R (2.94-fold) and protein levels increased significantly at 24 h (1.45-fold) ; increased transcript levels were also observed in nonischaemic lobes (1.78-fold). Superoxide dismutase prevented I\R and the increases in transcript and protein levels in ischaemic and non-ischaemic lobes.