TPP Conjugated AntioxidantsTriphenylphosphonium ion (TPP) has been successfully used to deliver several lipophylic antioxidants to the mito- chondrial matrix, including Mito-Q (coenzyme Q), mitovita- min E, and mitophenyltertbutyline as well as SkQ1 (plasto- quinone). These mitochondrial-targeted drugs can achieve concentrations in the mitochondrial matrix 100- to 1000-fold higher than those in the cytosol because of their strong positive charge, as mitochondria have a highly negative membrane potential (approximately 150 mV). Mito-Q pre- treatment has been shown effective in reducing ischemia– reperfusion injury in the isolated perfused hearts. Likewise, SkQ1 has also been shown to reduce infarct size in rodent model of coronary artery ligation. A recent study in sponta- neous hypertensive rats demonstrated that MitoQ treatment for 8 weeks significantly reduced systolic blood pressure and reduced cardiac mass.93 The blood pressure lowering effect might be explained by the improved bioavailability of endo- thelial nitric oxide. The efficacy of MitoQ to reduce blood pressure provides proof of concept that mitochondria-targeted antioxidants may confer vasoprotection in aging as well.