Prostaglandin Inactivation in Normal and Sensitized Guinea-pig Lung and its Inhibition by Indomethacin

Abstract

Based on the evidence of a rapid removal of prostaglandins (PGs) in the lung, inhibition of the pulmonary removal of PGE₁ and PGF_2α, was studied with isolated guinea-pig lungs. 1) In normal lungs, the average percent inactivation of PGE₁ and PGF_2α (5ng/ml) were 83.67±8.73% and 80.92±8.49%, respectively. 2) The percent inactivation of PGF₁ and PGF_2α decreased with increasing doses. 3) In normal lungs, the average percent inactivations of PGE₁ and PGF_2α, were 20.52±5.33% and 23.31±8.27%, respectively, with continuous infusion of indomethacin. 4) In sensitized lungs, the average percent inactivations of PGE₁ and PG_2α (5ng/ml) were 37.44±13.13% and 35.12±13.44%, respectively. 5) These results demonstrate that indomethacin has an inhibitory activity on PG inactivation, in addition to its already established activity on PG biosynthesis and that sensitization of lungs also inhibits inactivation of PGs per fused through the pulmonary vasculature.