TY - JOUR
T1 - Astrocyte regulation of blood flow in the brain
AU - Macvicar, Brian A.
AU - Newman, Eric A.
N1 - Publisher Copyright:
© 2015 Cold Spring Harbor Laboratory Press; all rights reserved.
PY - 2015
Y1 - 2015
N2 - Neuronal activity results in increased blood flow in the brain, a response named functional hyperemia. Astrocytes play an important role in mediating this response. Neurotransmitters released from active neurons evoke Ca2+ increases in astrocytes, leading to the release of vasoactive metabolites of arachidonic acid from astrocyte endfeet onto blood vessels. Synthesis of prostaglandin E2 (PGE2) and epoxyeicosatrienoic acids (EETs) dilate blood vessels, whereas 20-hydroxyeicosatetraenoic acid (20-HETE) constricts vessels. The release of K from astrocyte endfeet may also contribute to vasodilation. Oxygen modulates astrocyte regulation of blood flow. Under normoxic conditions, astrocytic Ca2+ signaling results in vasodilation, whereas under hyperoxic conditions, vasoconstriction is favored. Astrocytes also contribute to the generation of vascular tone. Tonic release of both 20-HETE and ATP from astrocytes constricts vascular smooth muscle cells, generating vessel tone. Under pathological conditions, including Alzheimer’s disease and diabetic reti-nopathy, disruption of normal astrocyte physiology can compromise the regulation of blood flow.
AB - Neuronal activity results in increased blood flow in the brain, a response named functional hyperemia. Astrocytes play an important role in mediating this response. Neurotransmitters released from active neurons evoke Ca2+ increases in astrocytes, leading to the release of vasoactive metabolites of arachidonic acid from astrocyte endfeet onto blood vessels. Synthesis of prostaglandin E2 (PGE2) and epoxyeicosatrienoic acids (EETs) dilate blood vessels, whereas 20-hydroxyeicosatetraenoic acid (20-HETE) constricts vessels. The release of K from astrocyte endfeet may also contribute to vasodilation. Oxygen modulates astrocyte regulation of blood flow. Under normoxic conditions, astrocytic Ca2+ signaling results in vasodilation, whereas under hyperoxic conditions, vasoconstriction is favored. Astrocytes also contribute to the generation of vascular tone. Tonic release of both 20-HETE and ATP from astrocytes constricts vascular smooth muscle cells, generating vessel tone. Under pathological conditions, including Alzheimer’s disease and diabetic reti-nopathy, disruption of normal astrocyte physiology can compromise the regulation of blood flow.
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U2 - 10.1101/cshperspect.a020388
DO - 10.1101/cshperspect.a020388
M3 - Article
C2 - 25818565
AN - SCOPUS:84930450293
SN - 1943-0264
VL - 7
SP - 1
EP - 15
JO - Cold Spring Harbor Perspectives in Biology
JF - Cold Spring Harbor Perspectives in Biology
IS - 5
ER -