Abstract
We present the sequence of changes in nitric oxide (NO) and superoxide (O2-) over time in reperfusion injuries. We examined both the changes in NO and O2- over time and the blood flow in an isolated ischaemia-reperfusion muscle model in rabbits. The ischaemic group comprised 8 animals which had had vascular pedicles clamped on to their rectus femoris muscles for 4 hours. The control group (n = 6) had a sham operation. Blood samples from the femoral vein proximal to the clamping point were collected before the operation, before clamping, before reperfusion, immediately after reperfusion, and 5, 15, 30, 60, and 120 minutes after reperfusion. NO was measured by Griess' method, and O2- by chemiluminescence. Blood flow was measured with a laser Doppler flowmeter. The amount of NO increased significantly immediately after reperfusion, and 15 and 30 minutes after reperfusion in the ischaemic group, compared with the control group (p < 0.05). O2- increased significantly at 5, 15, 60, 90 and 120 minutes after reperfusion, compared with the control group (p < 0.05). The blood flow volume curve increased by 1.4 times about four minutes after reperfusion compared with previously. After this it gradually decreased. The adverse effects of O2- became apparent when NO was extinguished by O2-.