title: Induction of total insensitivity to capsaicin and hypersensitivity to garlic extract in human by decreased expression of TRPV1.
abstract: TRPV1 is a cation channel which is activated by temperature (> or =42 degrees C) and capsaicin. In the present study, we found a person with total insensitivity to capsaicin and attempted to unravel its causes. The expression levels of TRPV1 protein and mRNA in the cells of the person's buccal mucosa were less than half of those in a normal subject. Sequential analysis of mRNA and genomic DNA revealed several point mutations mostly in the second intron of the person's TRPV1. Interestingly, the subject showed hypersensitivity to garlic extract, but TRPA1 (allicin receptor) level was normal. These results suggest that the decreased expression of TRPV1 may be related to a functional knock out in capsaicin sensation and hypersensitivity to allicin in humans.
authors.affiliation: Department of Physiology, College of Medicine, Korea University, 126-1 Anam-Dong 5 Ga, Sungbuk-Gu, Seoul 136-705, Republic of Korea.
authors.forename: Joong Jean
authors.initials: JJ
authors.lastname: Park
authors.forename: Jaehee
authors.initials: J
authors.lastname: Lee
authors.forename: Myung Ah
authors.initials: MA
authors.lastname: Kim
authors.forename: Seung Keun
authors.initials: SK
authors.lastname: Back
authors.forename: Seung Kil
authors.initials: SK
authors.lastname: Hong
authors.forename: Heung Sik
authors.initials: HS
authors.lastname: Na
mesh_terms: D000498:Allyl Compounds / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D002211:Capsaicin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D007438:Introns; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D017354:Point Mutation; D011930:Reaction Time; D017423:Sequence Analysis, RNA; D013440:Sulfides / Q000494:pharmacology*; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
chemical_list: D000498:Allyl Compounds; D018712:Analgesics, Non-Narcotic; D013440:Sulfides; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; C038491:allyl sulfide; D002211:Capsaicin