Cooling inhibits capsaicin-induced currents in cultured rat dorsal root ganglion neurones.
Whole-cell and single-channel recordings from rat dorsal root ganglion neurones were used to investigate the temperature dependence of currents through the capsaicin receptor (vanilloid receptor 1, VR1). Reducing the temperature from 31 to 14 degrees C inhibited the current induced by 0.5 microM capsaicin by 80%. The Q(10) (temperature coefficient over a 10 degrees C range) of the whole-cell capsaicin-induced current was 2.3 between 10 and 30 degrees C. Single-channel recordings showed that this inhibition by cooling was due to a marked reduction in the open probability (Q(10)=8.2 between 10 and 30 degrees C). This effect can explain the pain relief and reduction in inflammation caused by strong cooling of the skin.
Babes
Alexandru
A
Department of Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independenţei 91-95, 76201 Bucharest, Romania.
Amuzescu
Bogdan
B
Krause
Ulrich
U
Scholz
Andreas
A
Flonta
Maria Luiza
ML
Reid
Gordon
G
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D002478:Cells, Cultured; D003080:Cold Temperature; D017679:Cryotherapy; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007036:Hypothermia, Induced; D007249:Inflammation / Q000378:metabolism* / Q000503:physiopathology; D009475:Neurons, Afferent / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009619:Nociceptors / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010146:Pain / Q000378:metabolism* / Q000503:physiopathology; D059408:Pain Management; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D011955:Receptors, Drug / Q000187:drug effects / Q000378:metabolism*; D050916:TRPV Cation Channels
D011955:Receptors, Drug; D050916:TRPV Cation Channels; C494484:TRPV1 receptor; D002211:Capsaicin