Release, spread and persistence of immunoreactive neurokinin A in the dorsal horn of the cat following noxious cutaneous stimulation. Studies with antibody microprobes.
In barbiturate anaesthetized spinal cats antibody microprobes were used to examine release of immunoreactive neurokinin A following cutaneous thermal and mechanical stimulation. In the absence of peripheral stimuli, microprobes detected a diffuse basal presence of immunoreactive neurokinin A. Noxious mechanical and to a lesser extent noxious thermal stimuli increased the levels of immunoreactive neurokinin A diffusely throughout the dorsal horn which, in many cases, spread into the adjacent white matter. These diffuse stimulus-evoked increases contrast with previous experiments where the same stimuli produced discrete focal increases in levels of immunoreactive substance P. Evidence was obtained that released immunoreactive neurokinin A persisted in the spinal cord for at least 30 min beyond the period of stimulation. Neurokinin A needs consideration as the agent responsible for the long-lasting increases in excitability of some spinal neurons found by several laboratories to follow a brief input from unmyelinated primary afferents.
Duggan
A W
AW
Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Studies, University of Edinburgh, U.K.
Hope
P J
PJ
Jarrott
B
B
Schaible
H G
HG
Fleetwood-Walker
S M
SM
D000818:Animals; D002415:Cats; D007150:Immunohistochemistry; D015288:Neurokinin A / Q000378:metabolism*; D009619:Nociceptors / Q000378:metabolism* / Q000502:physiology; D010146:Pain / Q000378:metabolism*; D012867:Skin / Q000294:innervation*; D013116:Spinal Cord / Q000378:metabolism* / Q000503:physiopathology
D015288:Neurokinin A