RT Journal Article
SR Electronic
T1 Unravelling the Mystery of Capsaicin: A Tool to Understand and Treat Pain
JF Pharmacological Reviews
JO Pharmacol Rev
FD American Society for Pharmacology and Experimental Therapeutics
SP 939
OP 971
DO 10.1124/pr.112.006163
VO 64
IS 4
A1 Jessica O'Neill
A1 Christina Brock
A1 Anne Estrup Olesen
A1 Trine Andresen
A1 Matias Nilsson
A1 Anthony H. Dickenson
A2 Annette C. Dolphin
YR 2012
UL http://pharmrev.aspetjournals.org/content/64/4/939.abstract
AB A large number of pharmacological studies have used capsaicin as a tool to activate many physiological systems, with an emphasis on pain research but also including functions such as the cardiovascular system, the respiratory system, and the urinary tract. Understanding the actions of capsaicin led to the discovery its receptor, transient receptor potential (TRP) vanilloid subfamily member 1 (TRPV1), part of the superfamily of TRP receptors, sensing external events. This receptor is found on key fine sensory afferents, and so the use of capsaicin to selectively activate pain afferents has been exploited in animal studies, human psychophysics, and imaging studies. Its effects depend on the dose and route of administration and may include sensitization, desensitization, withdrawal of afferent nerve terminals, or even overt death of afferent fibers. The ability of capsaicin to generate central hypersensitivity has been valuable in understanding the consequences and mechanisms behind enhanced central processing of pain. In addition, capsaicin has been used as a therapeutic agent when applied topically, and antagonists of the TRPV1 receptor have been developed. Overall, the numerous uses for capsaicin are clear; hence, the rationale of this review is to bring together and discuss the different types of studies that exploit these actions to shed light upon capsaicin working both as a tool to understand pain but also as a treatment for chronic pain. This review will discuss the various actions of capsaicin and how it lends itself to these different purposes.