Metabolism of a thromboxane A2 antagonist in isolated rat hepatocytes

Metabolism of a thromboxane A2 antagonist (+/-)-5-(Z)-7-(3-endo-phenylsulphonylaminobicyclo[2.2.1]hept-2- exoyl)- heptenoic acid (S-145) in isolated rat hepatocytes was examined by high-performance liquid chromatography and gas chromatography/mass spectrometry. As the hydrophobic metabolites, bis-nor S-145, tetra-nor S-145 and bis-nordihydro S-145 were identified, and two other products were estimated to be monohydroxylated S-145 and dehydrogenated S-145. On the basis of kinetics of S-145 metabolism, a metabolic pathway of S-145 in isolated hepatocytes is tentatively proposed.