Hypoxanthine and urate levels of plasma during and after hemorrhagic hypotension in dogs.

The plasma hypoxanthine concentrations increased during hemorrhagic hypotension in dogs. A venous-arterial hypoxanthine difference was found indicating metabolism of hypoxanthine in the lungs. A maximal hypoxanthine level was found during the hypotension, then the level decreased. This probably reflects peripheral vasoconstriction. During reinfusion of the blood, a new hypoxanthine peak was observed. The urate levels also increased during the hypotension. An arterial venous difference was found. This probably illustrates that hypoxanthine is metabolized to urate in the lungs. It is concluded that the increase of plasma hypoxanthine concentrations might reflect tissue hypoxia.