EFFECTS OF ACETYLSALICYLIC-ACID ON PULMONARY VASCULAR TONE AND MEMBRANE-PERMEABILITY IN BLOOD-PERFUSED DOG LUNG

We studied the effects of acetylsalicylic acid (ASA) on presser respon se, microvascular filtration coefficient (K-f), extravascular lung wat er, and plasma concentrations of cyclooxygenase- and 5-lipoxygenase-de rived products in 21 blood-perfused dog lungs with constant flow. The lungs were perfused for 1 h with an intrapulmonary injection of saline as vehicle (n = 5), a low dose of ASA [136 +/- 25 (SD) mu g/ml perfus ate; n = 5], a high dose of ASA (1,006 +/- 278 mu g/ml perfusate; n = 6), or alloxan (1,000 mg; n = 5). Alloxan significantly increased K-f and extravascular lung water, whereas neither the low nor high dose of ASA increased K-f or extravascular lung water. The ASA-induced increa se in vascular resistance did not correlate with the extent of the dec rease in perfusate 6-ketoprostaglandin F-1 alpha or the ratio of perfu sate 6-ketoprostaglandin F-1 alpha to thromboxane B-2. Moreover, ASA d id not enhance the generation of perfusate leukotrienes B-4, D-4, or E (4). We conclude elude that pulmonary microvascular permeability is un altered by ASA and that neither the decrease in plasma prostacyclin no r the increase in plasma sulfidopeptide leukotrienes may account for A SA-induced pulmonary vasoconstriction.