The effect of sodium nitroprusside on the metabolism of prostaglandin E2 in rat isolated lungs.

The effect of sodium nitroprusside on the pulmonary metabolism of prostaglandin E2 (PGE2) was investigated in isolated perfused rat lungs. 20 nmol of 14C-PGE2 was injected as a bolus into the pulmonary circulation and the metabolites were analysed from the nonrecirculating perfusion effluent. When sodium nitroprusside was infused into the pulmonary circulation at 1, 10 or 100 micrograms/ml, the amounts of different metabolites and unmetabolized PGE2 in the perfusion effluent were unchanged. The small increase in the perfusion pressure after PGE2 injection was, however, decreased by sodium nitroprusside. The present study indicates that the vascular effects of sodium nitroprusside are no due to the changed metabolism of PGE2 in the pulmonary circulation.