Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-9-22
pubmed:abstractText
The rostral ventromedial medulla (RVM) is an area of the brainstem involved in the descending modulation of nociception at the level of the spinal cord. Although the RVM is involved in the inhibition or facilitation of nociception, the underlying mechanisms are not understood. Here we examined the role of the neuropeptide substance P and neurokinin-1 (NK-1) receptors located in the RVM on withdrawal responses evoked by mechanical and heat stimuli applied to the rat hindpaw under normal conditions and during hyperalgesia produced by capsaicin. The mechanical withdrawal threshold was obtained using von Frey monofilaments applied to the plantar surface of the hindpaw. Sensitivity to heat was determined by measuring the latency to withdrawal from radiant heat applied to the plantar surface. Mechanical and heat hyperalgesia were defined as a decrease in withdrawal response threshold or latency, respectively. Rats were prepared with a chronic cannula and either vehicle or the NK-1 receptor antagonists, L-733,060 or RP-67580, was injected into the RVM. Paw withdrawal responses were obtained before and after RVM injection, and then at 5, 30, and 60 min after an intraplantar injection of capsaicin (10 microg). Injection of the NK-1 antagonists at doses of 0.5 pmol or higher did not alter withdrawal responses to mechanical or heat stimuli under normal conditions but reduced the duration of nocifensive behavior and the mechanical and heat hyperalgesia produced by capsaicin. These findings suggest that the activation of NK-1 receptors in the RVM contributes to the hyperalgesia produced by capsaicin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1872-6623
pubmed:author
pubmed:issnType
Electronic
pubmed:day
30
pubmed:volume
139
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34-46
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
NK-1 receptors in the rostral ventromedial medulla contribute to hyperalgesia produced by intraplantar injection of capsaicin.
pubmed:affiliation
Department of Diagnostic and Biological Science, School of Dentistry, University of Minnesota, 515 Delaware Street SE, Minneapolis, MN 55455, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, N.I.H., Extramural