Vanilloid receptor TRPV

Menon MS, Mulrennan S A, Everett CF, Thompson R, Morice AH (2005) Experience with baclofen in cough secondary to gastro-oesophageal reflux disease, Proc Am Thorac Soc 2 A323 MitcheU JE, Campbell AP, New NE et al (2005) Expression and characterization of the intracellular vanilloid receptor (TRPV-1) in bronchi from patients with chronic cough, Exp Lung Res 31 295-306... 

TRP —transient receptor potential channel TRPA—TRP ankyrin receptor subfamily TRPC—TRP canonical receptor subfamily TRPM—TRP melastatin receptor subfamily TRPML—TRP mucolipin receptor subfamily TRPN—TRP NOMPG receptor family TRPP—TRP polycystin receptor subfamily TRPV—TRP vanilloid receptor subfamily TTX—tetrodotoxin... 

Mezey E, Toth ZE, Cortright DN, Arzubi MK, Krause JE, Elde R, Guo A, Blumberg PM, Szallasi A. Distribution of mRNA for vanilloid receptor subtype 1 (TRPVl), and TRPV 1-like immunoreactivity, in the central nervous system of the rat and human. Proc. Natl. Acad. Sci. U.S.A. 97,3655-3660 (2000). 

Recently, it has been reported that the expression of transient receptor potential vanilloid-1 (TRPV-1) is enhanced in airway nerves of patients with chronic cough (Groneberg et al. 2004). In addition to TRPV-1, acid-sensing ion channels are localized in A5-fibers of guinea pigs (Gu 2006). Therefore, differences in codeine sensitivity of acid-induced coughs may depend on the pH of the cough induction site. Further studies are needed to clarify such differences. 

TRPV channels are further classified into six subfamilies TRPVl, TRPV2, TRPV3, TRPV4, TRPV5, and TRPV6. The subtypes TRPV 1, 2, 3, and 4 are called thermo TRPs [4] since all of them are activated by different degrees of temperature. In 1997 the TRPVl (capsaicin, vanilloid) receptor was cloned from rodent posterior dorsal root ganglia [2] and since then has been studied extensively. Activation of TRPVl receptors is associated with pain formation... 

Mediator-induced inflammatory processes can lead to increased vascular permeability, neurogenic inflammation of airways and blood vessels, chemotaxis, and bronchospasm (Smith and Topford, 1999). Furthermore, capsaicin activates the vanilloid receptor family TRPVl (transient receptor potential cation channel subfamily V) within sensory neurons. Activation of these receptors leads to prolonged refractory periods and to a nonconducting desensitization. One study suggests that TRPV pathways may not be enhrely responsible for all of the adverse reactions caused by capsaicin (Holzer, 1991). 

Highly sensitive targeted lipidomic approaches are rapidly leading to the identification of new analogs of anandamide (Tan et al., 2006). The two major families of lipids that share common chemical structure with anandamide are FAEs and fatty acid amides. Although many of these lipids show no activity at CB receptors, they are known to bind and activate other receptors, such as transient receptor potential vanilloid type-1 (TRPV-1) and the nuclear receptor peroxisome proliferator-activated (PPAR-a). 

Cabranes A, Venderova K, de Lago E, Fezza F, Valenti M, Sdnchez A, Garcfa-Merino A, Ramos JA, Di Marzo V, Fernandez-Ruiz J (2005) Decreased endocannabinoid levels in the brain and beneficial effects of certain endocannabinoid uptake inhibitors in a rat model of multiple sclerosis involvement of vanilloid TRPV 1 receptors. Neurobiol Dis (in press)... 

In the bronchus, LOX inhibitors modestly attenuate the contractile action of capsaicin (Craib et al., 2001), raising the possibihty that the increase in intracellular calcium elicited by TRPV 1 receptor activation leads to the release of arachidonic add or anandamide or both, whose hydrox-ylation by LOX may lead to the formation of compounds that are themselves vanilloid agonists. 

Transient receptor potential (TRP) channels play an important role in a diversity of sensory function, including taste, smell, hearing and perception of pain. This family comprises proteins with six transmembrane-spanning domains that are assembled either as homotetramers or heterotetramers to form non-selective cation channels permeable to calcium and sodium ions. There are at least six subfamilies, including TRPC (canonical), TRPM (melastatin), TRPV (vanilloid), TRPA (ankyrin), TRPML (mucolipin) and TRPP (polycystin) (Nilius et al. 2007). 

TRPV-1 Transient receptor potential vanilloid-type 1... 

Pharmacologically, evodiamine has been widely studied as innovative antiobesity agent and was classified as a full TRPV-1 (transient receptor potential vanilloid-type 1) agonist. This receptor is a nonspecific ion chaimel and is activated by not only chemical compounds containing vanUlyl moiety but also heat (>45 °C) and acid (micromolar range) stimuli. It exhibited binding affinity similar to capsaicin in Chinese hamster ovary cell model. Despite similar in vitro and in vivo anti-obese activities between these compounds, evodiamine has not perceptible taste, including a peppery hot taste [80, 81]. 

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