Characterization of the antioxidant properties of pentaerithrityl tetranitrate (PETN)-induction of the intrinsic antioxidative system heme oxygenase-1 (HO-1).

Organic nitrates are among the oldest and yet most commonly employed drugs in the chronic therapy of coronary artery disease and congestive heart failure. While they have long been used in clinical practise, our understanding of their mechanism of action and of their side effects remains incomplete. To date, the most commonly employed nitrates are isosorbide mononitrate (ISMN), isosorbide dinitrate (ISDN), and nitroglycerin (GTN). Another nitrate, pentaerithrityl tetranitrate (PETN), has long been employed in eastern European countries and is currently being reintroduced also in western countries. So far, PETN is the only organic nitrate in clinical use, which is devoid of induction of oxidative stress and related side-effects such as endothelial dysfunction and nitrate tolerance. Some of these effects are related to special pharmacokinetics of PETN, but upon chronic administration, PETN also induces antioxidative pathways at the genomic level, resulting in increased expression of heme oxygenase-1 (HO-1) and ferritin, both possessing highly protective properties. There is good experimental evidence that at least part of the beneficial profile of long-term PETN treatment is based on activation of the heme oxygenase-1/ferritin system.