Open AccessPeripheral and Central Actions of Capsaicin and VR1 Receptor
Author(s) -
Takashi Sasamura,
Yasushi Kuraishi
Publication year - 1999
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.80.275
Subject(s) - capsaicin , trpm8 , desensitization (medicine) , receptor , chemistry , endocrinology , medicine , thermoregulation , sensory system , thermoreceptor , trpv1 , neuroscience , biology , transient receptor potential channel
Vanilloid receptor subtype 1 (VR1), a capsaicin receptor, is expressed in primary sensory neurons and vagal nerves. Heat and protons as well as capsaicin activate VR1 to induce the influx of cations, particularly Ca2+ and Na+ ions. Characteristic effects of capsaicin are the induction of a burning sensation after acute administration and the desensitization of sensory neurons after large doses and prolonged administration. The latter feature made capsaicin cream applicable for the treatment of chronic pain and pruritus. Capsaicin alters several visceral functions, which may be mediated by action on vagal nerves and central neurons. Capsaicin affects thermoregulation after intra-hypothalamic injection and releases glutamate from the hypothalamus and cerebral cortex slices, while VR1-like immunoreactivity is not apparent in these regions. These findings taken together suggest the existence of other subtypes of vanilloid receptors in the brain.