The Three-Body Problem in Stress Biology: The Balance Between O2, NO, and H2S in the Context of Hans Selye’s Stress Concept

Hans Selye’s stress concept, first introduced in the 1930s, has undergone substantial evolution, extending beyond biology and medicine to influence diverse academic disciplines. Initially, Selye’s General Adaptation Syndrome (GAS) described nonspecific physiological responses to stressors exclusively in mammals, without addressing other biological systems. Consequently, the concept of stress developed independently in biology and medicine, shaped by distinct physiological contexts. This review provides a historical overview of stress research, highlights both parallels and divergences between the stress responses of plants and animals, and integrates insights from traditional Eastern philosophies. We propose an updated GAS framework that incorporates the dynamic balance among reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) within the broader context of oxidative stress. We highlight the ionotropic glutamate receptor (iGluR) family and the transient receptor potential (TRP) channel superfamily as minimal molecular architectures for achieving GAS. This perspective expands the classical stress paradigm, providing new insights into redox biology, interspecies stress adaptation, and evolutionary physiology.