The Different Effects of Resveratrol and Naringenin on Isolated Human Umbilical Vein: The Role of ATP‐Sensitive K⁺ Channels

Abstract

The blood flow from the placenta to the fetus depends on human umbilical vein (HUV) vascular tone. ATP-sensitive K(+) (K(ATP)) channels link the metabolic state of the cell to membrane potential, and their activation in the HUV represents protection against hypoxia. The aims of our study were to assess the effects of resveratrol and naringenin on the HUV and to define the roles of K(ATP) channels in their effects. Serotonin or 100 mM K(+) were used for precontraction of the HUV without endothelium. The cumulative concentration-response curves were obtained by adding increasing concentrations of resveratrol or naringenin. Glibenclamide was used, in order to test the role of K(ATP) channels in its effect. Resveratrol induced more potent vasodilatation of serotonin- and 100 mM K(+)-precontracted HUV than naringenin. Glibenclamide induced significant shift to the right of the concentration-response curves of resveratrol and P1075 (a specific opener of K(ATP) channels). Western blotting showed that HUV expressed protein Kir6.1. Thus, resveratrol and naringenin produce dilatation of HUV. It seems that K(ATP) channels are involved in the relaxation of HUV induced by resveratrol, while naringenin seems to interact with other ion channels. The K(+) channel-independent mechanism(s) of these polyphenols could not be excluded.

Antiarrhythmic mechanisms of Malbec wine and resveratrol in isolated rat heart

“…This study describes antiarrhythmic properties of Malbec wine and confirms resveratrol ones [25][26][27][28][29][30]. The electrophysiological mechanisms were different between them.…”

“…The concentration used in this study is also in agreement with previous publication showing its cardioprotective properties [25][26][27][28][29][30]. Unless specified, all the other reagents were from Sigma-Aldrich (Saint Louis MO, USA).…”

“…Resveratrol also preserved conduction during ischemia, but the main change observed was relative hyperpolarization. This could be attributed to the reported activation of IK ATP channels [26,27,31,[49][50][51]. During ischemia, this channel open do to ATP/ADP imbalance, oxidative stress and acidosis [46,[52][53][54].…”

“…For example, resveratrol content of Malbec was one thousand times lower than the one in Resveratrol group [12,20,21,56]. Also, most of the electrophysiological properties describe until now were obtained above the micromolar concentration range of resveratrol [25][26][27][28][29][30]. These concentrations are impossible to be achieved by Malbec or any red wine consumption alone [12,33].…”

“…High concentration of this stilbenoid is antiarrhythmic [25][26][27][28][29][30]. At micromolar concentrations, resveratrol inhibits voltage-sensitive calcium and potassium currents and activates ATP sensitive potassium channels (IK ATP ) [18,25,26,[29][30][31].…”