“High concentrations of … drugs phenylbutazone and oxyphenbutazone as well as of the nonacidic metabolites of metamizol, i.e. 4-… 4-aminoantipyrine, inhibited the release of the cyclo-oxygenase products of arachidonic acid metabolism , TXB2 and 6-keto-PGF1 alpha, and simultaneously … the release of LTC4-like immunoreactivity in hearts.”