Evidence that substance P may be a modulator rather than a transmitter of noxious mechanical stimulation.
Substance P (SP), injected intrathecally, produced a dose-related increase in responsiveness (hyperalgesia) in a pressure test for nociceptive thresholds. Pretreatment with two doses of SP produced complete desensitization to this response but did not alter base-line responsiveness. The hyperalgesic response to SP and the lack of change in base line following desensitization to SP suggest a modulator rather than a transmitter role for SP in the transmission of noxious mechanical stimulation.
D000818:Animals; D007278:Injections, Spinal; D008297:Male; D009619:Nociceptors / Q000187:drug effects; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012684:Sensory Thresholds / Q000187:drug effects; D013116:Spinal Cord / Q000378:metabolism; D013373:Substance P / Q000502:physiology*; D009435:Synaptic Transmission
D013373:Substance P