Abstract Body: The prevalence of hypertension in early adulthood among women is 3-times lower than in men; but with aging hypertension rate increases in women much steeper, and hypertensive vascular and kidney damage is significantly higher in women. Sex-specific aspects of hypertension are poorly understood, and clinical studies did not show protection by estrogen hormone therapy. Hypertension accounts for 1 in 5 deaths among American women, posing a greater burden for women than men. Meanwhile, female-specific aspects of hypertension are poorly understood, and women or female-specific risk factors are understudied. We propose that female antihypertensive protection is critically dependent on deacetylation of mitochondrial proteins. We found that essential hypertension is linked to hyperacetylation and inactivation of critical mitochondrial metabolic and antioxidant enzymes, long-chain acyl coenzyme A dehydrogenase (LCAD) and superoxide dismutase 2 (SOD2). Our mouse studies showed that female antihypertensive phenotype is linked to diminished acetylation of mitochondrial LCAD and SOD2 protecting endothelial cell metabolism and function. We hypothesized that LCAD-K318/322 and SOD2-K68 acetylation promotes female endothelial dysfunction and hypertension. To test this hypothesis, we have developed endothelial-specific acetylation mimetic LCADQ and SOD2Q knock-in mice by mutation of corresponding lysine residues to glutamine. We found significant impairment of endothelial-dependent relaxation in Ec^LCADQ female, but not male mice compared with wildtype littermates which was coupled with superoxide increase in Ec^LCADQ female but not in male mice (Figure 1). Ec^LCADQ female mice had more severe angiotensin II-induced endothelial dysfunction compared with wildtype mice. We found that both endothelial specific acetylation mimetic LCADQ and SOD2Q knock-in female mice lost antihypertensive phenotype and had higher blood pressure compared with angiotensin II-infused wild-type female mice. These studies demonstrate critical role of mitochondrial acetylation in endothelial dysfunction and hypertension suggesting that female antihypertensive phenotype is associated with the reduced mitochondrial acetylation protecting mitochondrial and endothelial functions. We suggest that targeting mitochondrial metabolic and antioxidant pathways can rescue female cardiovascular protection and improve treatment of endothelial dysfunction and hypertension.