Prostaglandin E a postulated mediator of neurovascular coupling, at low concentrations dilates whereas at higher concentrations constricts human cerebral parenchymal arterioles.

There is considerable controversy regarding the vasoactive action of prostaglandin E (PGE). On the one hand, indirect evidence implicates that astrocytic release of PGE contributes to neurovascular coupling responses mediating functional hyperemia in the brain. On the other hand, overproduction of PGE was also reported to contribute to cerebral vasospasm associated with subarachnoid hemorrhage.