Responsiveness of C-fiber nociceptors to punctate force-controlled stimuli in isolated rat skin: lack of modulation by inflammatory mediators and flurbiprofen.
Although cutaneous C-fiber nociceptors show dramatic inflammatory sensitization to heat, they do not appear to get sensitized to the mechanical stimulation by von Frey hairs. We employed force-controlled punctate electromechanical stimulation to receptive fields of 61 characterized C-fibers in the isolated rat skin-saphenous nerve preparation. In general: low-in contrast to higher-threshold units showed greater dynamic sensitivity and response magnitude, an earlier onset and a stronger degree of adaptation, the latter due to the linear rise of the force stimulus. On this methodological basis three groups of units were subject to a mix of inflammatory mediators, to flurbiprofen or to control solution. Subsequent mechanostimulation revealed a good reproducibility of the control response and no significant changes in the treatment groups. In conclusion, even refined mechanostimulation was unable to demonstrate sensitization of the predominant nociceptor classes in the rat skin.
Schlegel
T
T
Institut für Physiologie und Experimentelle Pathophysiologie, Universität Erlangen/Nürnberg, Universitätsstrasse 17, D-91054 Erlangen, Germany.
Sauer
S K
SK
Handwerker
H O
HO
Reeh
P W
PW
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D005480:Flurbiprofen / Q000494:pharmacology*; D006930:Hyperalgesia / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D066298:In Vitro Techniques; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D018836:Inflammation Mediators / Q000494:pharmacology*; D008465:Mechanoreceptors / Q000187:drug effects / Q000502:physiology; D040542:Mechanotransduction, Cellular / Q000187:drug effects / Q000502:physiology; D036421:Nerve Fibers, Unmyelinated / Q000187:drug effects / Q000502:physiology*; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology*; D010812:Physical Stimulation; D051381:Rats; D012867:Skin / Q000294:innervation* / Q000503:physiopathology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018836:Inflammation Mediators; D005480:Flurbiprofen