KCNN3 and Hypertension: Hypertension-related endothelial dysfunction may also compromise endothelium-dependent hyperpolarization (EDH), a vasorelaxant process driven by the agonist-evoked activation of small- and intermediate-conductance, Ca2+-activated K+ channels (KCa2.3 and KCa3.1, respectively) in the endothelium [12,13].