Different Efficacy of Anti-Inflammatory Drugs in Inhibiting the Reactions to Intradermal Phospholipase A and PGE2

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 PGE2— 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 PGE2.