Angiotensin-Related Peptides and Their Role in Pain Regulation.

Angiotensin (Ang)-generating system has been confirmed to play an important role in the regulation of fluid balance and blood pressure and is essential for the maintenance of biological functions. Ang-related peptides and their receptors are found throughout the body and exhibit diverse physiological effects. Accordingly, elucidating novel physiological roles of Ang-generating system has attracted considerable research attention worldwide. Ang-generating system consists of the classical Ang-converting enzyme (ACE)/Ang II/AT1 or AT2 receptor axis and the ACE2/Ang (1-7)/MAS1 receptor axis, which negatively regulates AT1 receptor-mediated responses. These Ang system components are expressed in various tissues and organs, forming a local Ang-generating system. Recent findings indicate that changes in the expression of Ang system components under pathological conditions are involved in the development of neuropathy, inflammation, and their associated pain. Here, we summarized the effects of changes in the Ang system on pain transmission in various organs and tissues involved in pain development process.