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

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. Copyright (C) 2014 John Wiley & Sons, Ltd.