FIG. 5. Hypothetical mode of action of 12-lipoxygenase metabolites in producing presynaptic inhibition of neurotransmitter release. For a detailed description, see text. CaM, calmodulin; CaMKII, Ca2+/calmodulin-dependent protein kinase II; G, G protein; 12-HPETE, 12-hydroperoxy-eicosatetraenoic acid; PLA2, phospholipase A2; P-protein, phosphoprotein.