Immunological and non-immunological synthesis and release of prostaglandins and thromboxanes from isolated guinea pig trachea

Specific radioimmunoassays were used to demonstrate the synthesis by the guinea pig trachea of 6-keto PGF1 alpha, TxB2, and PGF2 alpha in addition to PGE2. The rank order of both spontaneous and stimulated release was PGE2 greater than PGF2 alpha greater than 6-keto PGF1 alpha = TxB2. Ovalbumin-induced prostanoid release from sensitized tissue was antigen-specific. The release was unlikely to be secondary consequence of tracheal contraction since incubations with calcium ionophore A23187, at a concentration which produces an equivalent magnitude of contraction of sensitized trachea, did not induce a significant PG or Tx production. In contrast, significantly higher prostanoid synthesis was induced by A23187 in unsensitized than sensitized trachea. Thus sensitization altered the profile of arachidonic acid metabolism evoked by the ionophore.