Dual regulation of the cerebral microvasculature by epoxyeicosatrienoic acids

Epoxyeicosatrienoic acids (EETs) ave lipid metabolites that are synthesized : in vascular endothelial cells. They are released by stimulation of their muscarinic receptors and induce vaso-relaxation of cerebral blood vessels. In addition, cytochrome P450 epoxygenase cerebral which catalyze the format ion of the epoxyeicosatrienoic acids, especially after Stimulation by the e xcitatory neurotransmitter glutamate, are! present in astrocytes, an abunda nt cell type in the brain that extends foot processes onto the cerebral mic rovessels. Using a modification of nr efficient, recently developed, fluore scent assay, we have detected the presence of EETs in endothelial cells cul tured from the cortex of rat brains as well as in neonatal astrocytes. We p ropose that both these cell types provide a dual supply of EETs to increase cerebral blood flow? in order to meet systemic as well as localized nutrie nt demands of cells in the brain. (C) 2001, Elsevier Science Inc.