Fluoxetine Dilates Isolated Small Cerebral Arteries of Rats and Attenuates Constrictions to Serotonin, Norepinephrine, and a Voltage-Dependent Ca²⁺Channel Opener

Abstract

Fluoxetine elicits substantial dilation of isolated small cerebral arteries, a response that is not mediated by endothelium-derived dilator factors or activation of K(+) channels. The finding that fluoxetine inhibits constrictor responses to Ca(2+) channel opener, as well as serotonin and norepinephrine, suggests that fluoxetine interferes with the Ca(2+) signaling mechanisms in the vascular smooth muscle. We speculate that fluoxetine increases cerebral blood flow in vivo, which contributes to its previously described beneficial actions in the treatment of mental disorders.