Modulation of eicosanoid release from anaphylactic guinea-pig heart with 5-benzoyl-a-methyl-2-thiophene acetic acid (tiaprofenic acid).

The effects of infusion of the non-steroidal anti-inflammatory drugs (NSAID), tiaprofenic acid (2.2 micrograms/min or 10.0 micrograms/min) and indomethacin (1.0 microgram/min) on the release of leukotriene (LT) C4-like immunoreactivity, thromboxane (TX) B2 and 6-keto-prostaglandin (PG) F1 alpha from isolated perfused anaphylactic guinea-pig hearts were investigated. Tiaprofenic acid at both concentrations used significantly inhibited anaphylactic release of TXB2 and 6-keto-PGF1 alpha as did indomethacin (1.0 microgram/min) which was, however, about ten times more potent in this respect. Release of immunoreactive LTC4-like material was not influenced by the lower concentration of tiaprofenic acid used (2.2 micrograms/min), but significantly enhanced by the higher concentration (10.0 micrograms/min). Thus, the effect of tiaprofenic acid on eicosanoid release by the anaphylactic heart is very similar to that of indomethacin without any differential inhibition of TXB2 or 6-keto-PGF1 alpha formation.