Linked Life Data

10087019

Source:http://linkedlifedata.com/resource/pubmed/id/10087019

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-4-21
pubmed:abstractText
In rat dorsal root ganglion neurons, activation of kappa- and mu-opioid receptors decreases N-type calcium current, whereas a constitutively active form of protein kinase C (PKC; i.e., PKM, a PKC catalytic subunit fragment) increases N-type calcium current. PKC also attenuates inhibition of calcium current by several G protein-linked neurotransmitter systems. We examined the effects of activation of endogenous PKC by 4beta-phorbol 12-myristate 13-acetate (PMA) and dialysis of cells with PKM and a pseudosubstrate inhibitor PKC(19-31) (PKC-I) on kappa- and mu-opioid-mediated inhibition of calcium current, calcium current amplitude, and rundown. PMA modestly increased peak calcium current and substantially reduced calcium current "rundown," effects blocked by PKC-I. In contrast, PKC-I decreased calcium current and increased current rundown. PMA attenuated morphine-, dynorphin A-, and U50, 488- but not pentobarbitol-related inhibition of calcium current. Similar effects were seen with intracellular dialysis of PKM. Intracellular PKC-I did not block opioid inhibition of calcium current but did reverse PMA and PKM effects on opioid receptor coupling to calcium channels. Because neither PMA nor PKM changed the proportion of omega-CgTX-inhibited current, their effects were not due to a decrease in the proportion of N-type current. After omega-CgTX treatment, there were no differences in the dynorphin A effects on control and PMA- or PKM-treated neurons, suggesting that PKC primarily affected coupling to N-type calcium channels. These data suggest that in acutely dissociated rat dorsal root ganglion neurons, endogenous PKC is required for maintenance of calcium current, may play a role in regulation of neuronal calcium channels, and could be involved in tolerance and/or cross-talk inhibition of opioid responsiveness.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
289
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
312-20
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
kappa- and mu-Opioid inhibition of N-type calcium currents is attenuated by 4beta-phorbol 12-myristate 13-acetate and protein kinase C in rat dorsal root ganglion neurons.
pubmed:affiliation
Department of Neurology, University of Michigan, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.