Abstract
1.
1. Rabbit kidneys were clamped and rendered warm ischaemic (WI)
in situ for 60 and 120 min. They were then either removed immediately after the ischaemic insult or after reperfusion with blood for 60 min or 24 hr.
2.
2. Homogenates were assayed for phospholipid-Schiff base fluorescence (Ex. 360 nm, Em. 435 nm) and for diene conjugate formation by u.v. spectrophotometry (240 nm) as indices of lipid peroxidation.
3.
3. No alteration in tissue levels of Schiff base was evident immediately after WI but when the homogenates were incubated at 37°C for 90 min, the rate of peroxidation was significantly elevated compared to controls (
P < 0.02 after WI of 60 min and
P < 0.001 after 120 min of WI).
4.
4. These values were still further elevated after reperfusion with blood for 60 min and 24 hr (
P < 0.001).
5.
5. Diene conjugates were raised after WI alone and further still after reperfusion.
6.
6. Thus an early index of lipid peroxidation (diene conjugation) suggested peroxidative damage during the warm ischaemic period itself, whilst detection of Schiff bases was only possible after
in vitro incubation of the tissue.
7.
7. Both indices of oxygen-derived free radical damage were increased after reperfusion
in vivo with blood and may relate to the degree of tissue damage sustained during ischaemia and reflow.