Effect of XXXX and vasoactive intestinal peptide on cerebral blood flow.

@entity23153 @entity235 @entity26 @entity95 @entity1617 @entity3897 @entity934
These experiments were performed to determine whether the neurotransmitters @entity934 ( @entity1617 ) and vasoactive intestinal peptide ( @entity23153 ) increase cerebral blood flow (CBF). In anesthetized @entity235 , infusion of very large doses of @entity1617 (500 microgram/min) into the carotid artery increased CBF (measured with microspheres) 50%. Anatomical limitations prevented adequate testing of cerebrovascular responses in @entity235 . In anesthetized @entity95 , infusion of @entity1617 (10 microgram/min) into the carotid artery produced a twofold increase in CBF. Vessels in gray matter were more responsive than vessels in white matter. @entity1617 did not alter cerebral @entity26 consumption, which indicates that the dilator effect of the drug is not an indirect effect mediated through an increase in metabolism. The vasodilator response to @entity1617 was attenuated by @entity3897 (1 mg iv). Intracarotid infusion of @entity23153 in @entity95 increased blood flow to cerebral gray matter: infusion of @entity23153 (10 microgram/min) incresed flow 33%. We conclude that 1) cerebral vasodilator responses to @entity1617 and @entity23153 are larger than previously recognized and 2) responses to these drugs occur primarily in cerebral gray matter. Because the neurotransmitters increase CBF significantly, these studies should encourage further studies concerning effects of cholinergic and peptidergic nerves on cerebral vessels.
