The Therapeutic Potential of Gaseous Autacoids

Carbon monoxide (CO) and hydrogen sulfide (H2S) are small, lipid-soluble gaseous autacoids that modulate numerous physiological processes. Historically, both gases were considered highly noxious environmental hazards having well-defined modes of toxicity: CO binds avidly to hemoglobin reducing the oxygen-carrying capacity of the protein leading to tissue hypoxia while H2S is a potent mitochondrial poison that blocks cellular respiration. Surprisingly, research conducted in the past couple of decades discovered that CO and H2S are produced endogenously by mammalian cells and serve as important signaling molecules in the nervous, inflammatory, and cardiovascular systems. Recent experimental studies indicate that these gases act as vasodilators and elicit broad-spectrum anti-inflammatory, antioxidant, growthregulatory, and cytoprotective effects in animal models of hypertension, inflammation, sepsis, atherosclerosis, transplantation, and ischemiareperfusion injury [1-4]. These preclinical findings underscore the wide-ranging therapeutic potential of CO and H2S, and offer novel translational opportunities in treating multiple human diseases.