The metabolism of arachidonic acid in hamster lung microsomes is not completely inhibited by aspirin and indomethacin.

Aspirin (100 microM or 1 mM) or indomethacin (10 microM or 100 microM) was incubated with a microsomal preparation of hamster lungs in the presence of NADPH for 10 min. Then 14C-arachidonic acid (20 microM) was added and the incubation was continued for an additional 20 min. The metabolites were extracted with ethyl acetate first at pH 7.

The effect of aspirin pretreatment on the fate of arachidonic acid in hamster isolated lungs.

The fate of exogenous arachidonic acid (AA) was investigated in isolated perfused lungs from hamsters, which were pretreated with aspirin in drinking water (0, 5, 50 or 500 mg/1) for one week. When 40 nmol of 14C-AA was infused in two minutes into the pulmonary circulation, the perfusion pressure increased. This pressor response was decreased by 50 mg/1 aspirin and was negligible after 500 mg/1.