Alteration of plasma hypoxanthine concentration during ischaemia in the forelimb of the pig.

Ischaemia in the forelimb of pigs was induced by clamping the main artery of an 'isolated leg' preparation. In plasma from the brachial vein the hypoxanthine concentration increased linearly between 10 and 25 min of ischaemia. The average increase in plasma hypoxanthine concentration in ten experiments was 25-0 micromol/1 after 30 min of ischaemia. It is concluded that the plasma hypoxanthine level might be a useful indicator of tissue hypoxia caused by impairment of peripheral blood flow.