Interaction between Nitric Oxide and Thromboxane A2 in the Regulation of the Resting Cerebrovascular Tone

Nitric oxide (NO) plays an important role in the regulation of the cerebral blood flow (CBF) (for review see: Faraci and Heistad, 1998). Inhibition of the L-arginine—NO pathway results in cerebral vasoconstriction and reduction of the CBF, indicating that the basal release of NO provides a resting relaxant tone in the cerebrovascular bed (for review see: Iadecola et al., 1994). This effect of basal NO production has generally been regarded as a direct relaxant action on the smooth muscle. The possibility that NO may regulate the resting cerebrovascular tone by modulation of the prostanoid synthesis has not been investigated to date.