Epoxyeicosatrienoic acids (EETs), which are synthesized from arachidonic acid by 
cytochrome P450 epoxygenases, function primarily as autocrine and paracrine 
effectors in the cardiovascular system and kidney. They modulate ion transport 
and gene expression, producing vasorelaxation as well as anti-inflammatory and 
pro-fibrinolytic effects. EETs are incorporated into the sn-2 position of 
phospholipids and are rapidly mobilized when a cell is treated with a Ca(2+) 
ionophore, suggesting that they may play a role in phospholipid-mediated signal 
transduction processes. Soluble epoxide hydrolase (sEH) converts EETs to 
dihydroxyeicosatrienoic acids (DHETs), and inhibition of sEH is a potential 
approach for enhancing the biological activity of EETs. EETs also undergo 
chain-elongation and beta-oxidation, and the accumulation of partial 
beta-oxidation products increases when sEH is inhibited. Some functional effects 
of EETs occur through activation of either the guanine nucleotide binding 
protein Galphas or the Src signal transduction pathways, suggesting that EETs 
act by binding to membrane receptors. However, other evidence indicates that the 
modulation of gene expression occurs through an intracellular action of EETs. 
Because of the diversity of biochemical and functional responses produced by 
EETs, it is doubtful that a single mechanism or signal transduction pathway can 
account for all of their actions.