Possible role of nitric oxide in cutaneous pathophysiology

Known for a long time only for its characteristics of corrosive agent and pollutant, nitrogen oxide (commonly, although improperly, named nitric oxide) is a gas whose biological activities have been extensively studied only in the last 16 years, when it was identified as a universal mediator in many living organisms (microorganisms, plants, animals) and in various organic functions. In human being, 3 different isoforms of the enzyme deputed to nitric oxide synthesis have been identified and studied, showing that this mediator is ubiquitous, how important it is in maintaining homeostasis, and that alterations to its synthesis are present in several diseases. Since the first studies on nitric oxide and the cardiovascular system, research has widened its horizon focusing attention, in the last 5 years, on the relationship between nitric oxide and skin. Although the relatively young age of this research field does not allows certain conclusions, studies performed have given us better comprehension of some physiological and pathological phenomena, and have sometimes significantly extended, or changed, formerly unquestioned theories and axioms. A review is presented of current knowledge on possible relations between nitric oxide and skin, and of possible future therapeutic perspectives based on the exogenous modulation of inflammation with nitric oxide synthase inhibitors or nitric oxide-releasing drugs.