Possible Interaction: Norepinephrine and Quercetin

“ Norepinephrine-induced increase of [Ca2+]i was inhibited by the tyrosine kinase inhibitors quercetin and tyrphostin by 23.8% and 21.4%, respectively, but the accumulation of [3H]InsPs induced by norepinephrine was not.”

“ Quercetin supplementation resulted in higher noradrenaline concentrations and enhanced peak absorption and oxidation of [(13)C6]-glucose by 10%.”

“This conclusion is supported by the following observations: 1) noradrenalin reversed the reduction of I(sc) produced by both carbachol and quercetin ; 2) the flavonol was ineffective in tissues in which the muscarinic agonist had already elicited its maximal reduction of I(sc).”

“3) NE and Ang II could increase Ca-SHR more significantly than Ca-WKY (P < 0.05), TFH, Que and Isor had remarkably inhibitory effect on the elevation of Ca-SHR and Ca-WKY induced by NE or Ang II. (”

“4) In the absence of extracellular Ca(2+), TFH, Que and Isor also had certain inhibitory effect on Ca-SHR and Ca-WKY induced by NE , and the effect on the former was more significant than that on the latter (P < 0.05).”

“After 4 weeks, addition of quercetin (0.1 microM-1 mM) caused a significant dose-dependent relaxation of noradrenaline (NA)- and KCl-preconstricted rings in both control and diabetic groups with a significant inter-group difference of P<0.01.”

“Both resveratrol and quercetin dose-dependently inhibited the contractile response to noradrenaline (NA) in isolated endothelium-intact rat aorta.”

“Both quercetin and staurosporine inhibited the contractions induced by 10(-5) M noradrenaline , 10(-5) M 5-HT and 20 mM caffeine in Ca(2+)-free solution.”

“ Quercetin , 10(-6)-10(-4) M, inhibited in a concentration-dependent manner the contractions induced by noradrenaline , high KCl and Ca2+, this effect being observed when the drug was added before or after the induced contractions.”

“It is possible that quercetin enhances the plasma norepinephrine level and/or increases the level of UCP1 in the white and/or brown adipose tissue by direct effects, independent of sympathetic stimu-”

“Third, even though quercetin may enhance the plasma norepinephrine level, it should be confirmed that the increased level of UCP1 in the white and/or brown adipose tissue is induced by direct effects of downstream of β-adrenergic receptor stimulation through experiments involving blockade of β-adrenergic receptor.”

“Further studies are needed to determine how quercetin enhances plasma norepinephrine and β3-adrenergic receptor mRNA in the adipose tissues, as well as the stress issue.”

“ Quercetin supplementation enhanced the plasma norepinephrine level and tended to upregulate β3-adrenergic receptor mRNA level in the WAT of HFD-fed obese mice, accompanied by AMP-activated protein kinase (AMPK) activation.”