PKA-dependent activation of the vascular smooth muscle isoform of KATP channels by vasoactive intestinal polypeptide and its effect on relaxation of the mesenteric resistance artery.

ABSTRACT: Vasoactive intestinal polypeptide (VIP) is a potent vasodilator and has been successfully used to alleviate hypertension. Consistently, disruption of VIP gene in mice leads to hypertension. However, its downstream targets in the vascular regulation are still not well demonstrated. To test the hypothesis that the vascular smooth muscle isoform of KATP channels is a downstream target of the VIP signaling, we performed the studies on the Kir6.1/SUR2B channel expressed in HEK293 cells. We found that the channel was strongly activated by VIP. Through endogenous VIP receptors, the channel activation was reversible and dependent on VIP concentrations with the midpoint-activation concentration approximately 10 nM. The channel activation was voltage-independent and could be blocked by KATP channel

SUBMITTER: Yang Y 

PROVIDER: S-EPMC2245864 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature