Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1998-7-1
pubmed:abstractText
To investigate the effects of changes in intracellular cAMP on alpha 2-adrenoceptor (AR)-induced inhibition of airway acetylcholine (ACh) release, we examined the effects of the alpha 2-AR agonist clonidine on electrical field stimulation-evoked ACh release from equine tracheal parasympathetic nerves before and after treatment with 8-bromo-cAMP or forskolin. We also tested whether charybdotoxin (ChTX)- or iberiotoxin (IBTX)-sensitive Ca(2+)-activated K+ channels mediate alpha 2-AR-induced inhibition by examining the effect of clonidine in the absence and presence of ChTX or IBTX on ACh release. The amount of released ACh was measured by HPLC coupled with electrochemical detection. Clonidine (10(-7) to 10(-5) M) dose dependently inhibited ACh release before and after treatment with 8-bromo-cAMP (10(-3) M) or forskolin (3 x 10(-5) M). ChTX and IBTX, both at the concentration of 5 x 10(-7) M, significantly increased ACh release; however, they did not alter the magnitude of clonidine-induced inhibition. These results indicated that in equine tracheal parasympathetic nerves, alpha 2-AR-induced inhibition of ACh release is via an intracellular cAMP-independent pathway. Activation of both ChTX- and IBTX-sensitive Ca(2+)-activated K+ channels inhibits the electrical field stimulation-evoked ACh release, but these channels are not involved in the alpha 2-AR-induced inhibition of ACh release.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/8-Bromo Cyclic Adenosine..., http://linkedlifedata.com/resource/pubmed/chemical/Acetylcholine, http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Agonists, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Charybdotoxin, http://linkedlifedata.com/resource/pubmed/chemical/Clonidine, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/Forskolin, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channel Blockers, http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Adrenergic, alpha, http://linkedlifedata.com/resource/pubmed/chemical/iberiotoxin
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
L827-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Role of cAMP and neuronal K+ channels on alpha 2-AR-induced inhibition of ACh release in equine trachea.
pubmed:affiliation
Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824-1314, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't