Involvement of the Renin-Angiotensin System in Stress: State of the Art and Research Perspectives.

Along with other canonical systems, the renin-angiotensin system (RAS) has shown essential roles in stress. This system is a complex regulatory proteolytic cascade composed of various enzymes, peptides, and receptors. Besides the classical (ACE/Ang II/AT 1 receptor) and the counter-regulatory (ACE2/Ang-(1-7)/Mas receptor) RAS axes, evidence indicates that non-classical components, including Ang III, Ang IV, AT 2, and AT 4, can also be involved in stress. Objective and methods: This comprehensive review summarizes the current knowledge on the participation of RAS components in different adverse environmental stimuli stressors, including air-jet stress, cage switch stress, restraint stress, chronic unpredictable stress, neonatal isolation stress, and post-traumatic stress disorder. Results and conclusion: In general, activating the classical RAS axis potentiates stress-related cardiovascular, endocrine, and behavioral responses, while the stimulation of the counter-regulatory axis attenuates these effects. Pharmacological modulation in both axes is optimistic, offering promising perspectives for stress-related disorders treatment. In this regard, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are potential candidates already available because they block the classical axis, activate the counter-regulatory axis, and are safe and efficient drugs.