Impact of whole body passive heat stress and arterial shear rate modification on radial artery function in young men

Abstract

We observed that acute whole body heating elevates radial artery shear rate, diameter, and blood flow. This results in a diminished flow-meditated dilatation (FMD) but does not change low-flow-mediated constriction (L-FMC). Preventing shear rate changes during whole body heating reduces radial artery vasodilation and reverses FMD reductions but has no effect on L-FMC. These findings indicate that shear rate changes underpin conduit artery responses to acute whole body heat stress, but further endothelium-dependent flow-mediated vasodilation is attenuated as the vasodilatory range limit is approached.