FMO5 and Hypertension: Normalization of endothelial function by spironolactone (Quaschning et al., 2001) or eplerenone (Quaschning et al., 2001; Sanz-Rosa et al., 2005) through an increase in eNOS protein and the reduction of elevated NADPH oxidase activity was previously observed in several models of hypertension (Harvey et al., 2017).