Functional Hyperemia in the Brain Hypothesis for Astrocyte-Derived Vasodilator Metabolites

摘要: Background —Cerebral blood flow is tightly coupled to neuronal metabolic activity, a phenomenon referred as functional hyperemia. The mechanisms underlying hyperemia in the brain have been extensively studied, but link between activation and nutritive has yet be defined. Recent investigations by our laboratory others identified potential role for astrocytes an intermediary cell type this process. Summary of Review —This short review will develop hypothesis that cytochrome P450 epoxygenase activity catalyzes formation epoxyeicosatrienoic acids (EETs), which act potent dilators cerebral vessels are released response glutamate receptor within astrocytes. Neuronal stimulates release arachidonic acid from phospholipid pool astrocytic membranes. We provide evidence on stimulation receptors metabolized 2C11 cDNA enzymes into EETs. Conclusions —The EETs thus formed activate K+ channels, increase outward current, hyperpolarize plasma membrane. resulting membrane hyperpolarization inhibits voltage-gated Ca2+ channels leads arteriolar dilation, thereby increasing regional activity.