Different Efficacy of Anti-Inflammatory Drugs in Inhibiting the Reactions to Intradermal Phospholipase A and PGE 2

Abstract

The increase in local vascular permeability caused by intradermal injection of Phospholipase A is antagonized by both steroidal and non-steroidal antiinflammatory drugs at dose levels roughly equieffective in carrageenin oedema test. In the same range of doses these drugs are scantly effective against PGE ₂—induced increase of vascular permeability. Since it is generally accepted that Phospholipase A stimulates prostaglandin formation and alters cell membranes function the effect of non-steroidal drugs is interpreted as an inhibition of prostaglandin biosynthesis and the effect of steroidal drugs as a membrane stabilization. In addition the results indicate that both steroidal and non-steroidal drugs are devoid of a direct antagonistic effect towards the increase of vascular permeability induced by PGE ₂.