Arachidonic acid is metabolized through the 12-lipoxygenase (12-LOX) and the cytochrome P-450 pathways to produce 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE, 1a) and 12(R)-hydroxyeicosatetraenoic acid (12(R)-HETE, 1b), respectively. These two endogenous substances have recently been discovered to be implicated in a number of important biological activities such as hypertension, thrombosis, metastasis of tumor cell, angiogenesis, and ...