Vasodilation of quercetin on rat renal artery and the relationship with L-type voltage-gated Cachannels and protein kinase C / 生理学报

ABSTRACT

To investigate the diastolic function of quercetin on rat renal artery in vitro and its mechanism, the tension of rat renal artery was recorded by multi myograph system, and the L-type voltage-gated Ca channels (LVGC) current was recorded by whole-cell patch clamp technique. Quercetin produced relaxation effect on rat renal artery pre-contracted by 60 mmol/L KCl or 1 × 10 mol/L phenylephrine, and the maximal diastolic percentage was  (84.53 ± 7.35)% or (76.42 ± 4.63)%. There was no statistical difference in the maximal diastolic percentage between endothelium-intact and endothelium-denuded groups. Pre-incubation of protein kinase C (PKC) inhibitor C6303 inhibited the maximal diastolic amplitude induced by quercetin. The peak current density of LVGC in rat renal artery vascular smooth muscle cells (VSMCs) was (23.17 ± 1.33) pA/pF. Quercetin (10 μmol/L) inhibited the peak current to (10.46 ± 1.35) pA/pF, and the inhibition percentage was 54.86%. C6303 (1 μmol/L) partially reversed the inhibitory effect of quercetin, and the inhibition percentage was 62.08% (P < 0.05). These results suggest that quercetin can relax rat renal artery in vitro in a concentration-dependent and endothelium-independent manner. The vasodilation of quercetin may be related to inhibition of LVGC current and activation of PKC.