Linked Life Data

14769376

Source:http://linkedlifedata.com/resource/pubmed/id/14769376

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-2-10
pubmed:abstractText
Intraplantar formalin injection is widely used as an experimental model of tonic pain. We investigated the role of endogenous micro-opioid receptor mechanisms in formalin-induced nocifensive behavior in mice. The flinching response induced by formalin (2%, 20 microl) was studied in mice with normal (wild type, n = 8) and absent (homozygous micro-opioid receptor knockout, n = 8) micro-opioid receptor levels. The flinch responses were counted every 5 min for 60 min post-formalin injection. Lumbar spinal cord (L4, 5) was harvested 2 h post-formalin injection to examine c-Fos expression using immunohistochemistry. The effects of naloxone (5 mg/kg, sc) administered 30 min before the intraplantar formalin injection on the flinching response of wild-type mice (n = 7) were also recorded. The second-phase formalin response (10-60 min after formalin) was higher in homozygous micro-opioid receptor knockout mice compared to the wild-type mice (P < 0.01). Naloxone administration in wild-type mice before formalin injection resulted in pain behavior similar to that observed in homozygous micro-opioid receptor knockout mice (P > 0.05). The c-Fos expression induced by formalin injection in the knockout mice was not different from that observed in wild-type mice. Our results suggest that the endogenous micro-opioid system is activated by intraplantar formalin injection and exerts a tonic inhibitory effect on the pain behavior. These results suggest an important modulatory role of endogenous micro-opioid receptor mechanisms in tonic pain states.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0014-4886
pubmed:author
pubmed:issnType
Print
pubmed:volume
184
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
839-45
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Role of micro-opioid receptors in formalin-induced pain behavior in mice.
pubmed:affiliation
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.