12/15-lipoxygenase, oxidative modification of LDL and atherogenesis

Lipoxygenases comprise a family of non-henze iron-containing dioxygenases t hat stereospecifically insert molecular oxygen into free or esterified poly unsaturated fatty acids. The dual specificity 12/15-lipoxygenases have been implicated in the oxidative modification of low-density lipoproteins and f oam cell formation primarily based on in vitro studies. Recent in vivo data obtained with 12/15-lipoxygenase-deficient mice crossbred to apolipoprotei n E-deficient mice have established a pro-atherogenic role for this pathway . In contrast, previous experiments with macrophage expressing 15-lipoxygen ase transgenic rabbits have suggested an anti-atherogenic role. Possible ex planations are presented that may elucidate these differences. (C) 2001, El sevier Science Inc.