REVIEW: Evidence supporting the 'preparation for oxidative stress' (POS) strategy in animals in their natural environment

Comp Biochem Physiol A Mol Integr Physiol. 2024 Mar 21:111626. doi: 10.1016/j.cbpa.2024.111626. Online ahead of print.ABSTRACTHypometabolism is a common strategy employed by resilient species to withstand environmental stressors that would be life-threatening for other organisms. Under conditions such as hypoxia/anoxia, temperature and salinity stress, or seasonal changes (e.g. hibernation, estivation), stress-tolerant species down-regulate pathways to decrease energy expenditures until the return of less challenging conditions. However, it is with the return of these more favorable conditions and the reactivation of basal metabolic rates that a strong increase of reactive oxygen and nitrogen species (RONS) occurs, leading to oxidative stress. Over the last few decades, cases of species capable of enhancing antioxidant defenses during hypometabolic states have been reported across taxa and in response to a variety of stressors. Interpreted as an adaptive mechanism to counteract RONS formation during tissue hypometabolism and reactivation, this strategy was coined "Preparation for Oxidative Stress" (POS). Laboratory experiments have confirmed that over 100 species, spanning 9 animal phyla, apply this strategy to endure harsh environments. However, the challenge remains to confirm its occurrence in the natural environment and its wide applicability as a key survival element, through controlled experimentation in field and in natural conditions. Even under such conditions, numer...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - Category: Physiology Authors: Source Type: research