Oxidative stress: physiopathology and laboratory diagnosis

Abstract

Oxidative stress is a metabolic disorder in which unstable molecules, also called reactive species, cause cellular injury due to oxidation-reduction reactions with organic molecules, such as phospholipids, proteins and DNA. These injuries can lead to loss of cellular function and, consequently, important dysfunctions in organic systems. These species are constantly formed in the normal cellular physiology, either through the metabolism of oxygen or amino acids, generating, respectively, reactive oxygen species (EROS) and reactive nitrogen species (RNSN). Due to the toxic potential of these molecules, endogenous and exogenous protective mechanisms, represented by the antioxidant agents, come into action to neutralize these compounds and prevent cellular injury. When the production of these species exceeds the antioxidant capacity of the organism, the cellular metabolism enters into oxidative stress. In certain cases, the EROS and ERNS productions become desirable, as an example in inflammatory disorders, where they will participate in the production of inflammatory mediators, but the exacerbation of this production can be detrimental and it is important to know the oxidative status to control the progression of the disorder in sick animals. In this context, it is necessary to know the biochemical profile of oxidative and antioxidant compounds in clinical and hospital routine of small and large animals. The objective of this study was to elucidate the pathophysiological mechanisms of oxidative stress as well as the available laboratory diagnostic methods to explain the importance of oxidative stress in clinical practice, so that the determination of these compounds is included in the medical and hospital routine.