Pulmonary removal of [3H]prostaglandin (PG)E1 was measured from multiple indicator dilution techniques using [14C]dextran as an intravascular marker in mechanically ventilated anesthetized rabbits. Removal of PGE1 was 87 +/- 1% (n = 23) at the peak of the [14C]dextran outflow curve and decreased in a dose-dependent manner when: 1) indocyanine green (ICG) was coadministered in the injection mixture (n = 18; IC50 = 16 microM); or 2 ICG was administered i.v. to achieve a steady-state level (n = 5; IC50 = 80 microM). Cumulative doses of either furosemide (0.1 mmol/kg b.wt.; n = 5) or probenecid (1.0 mmol/kg; n = 10) administered over 2 hr did not significantly affect the removal of PGE1. However, when 0.5 mumol of ICG was added to the injection, both furosemide and probenecid (0.01 mmol/kg) were associated with greater decreases in the removal of PGE1 than would be expected by the effect of ICG alone (P less than .01). These data show that in vivo measurements of pulmonary removal of [3H]PGE1 are predictably affected by various inhibitors of this transport process previously shown in isolated perfused lungs.