Linked Life Data

1649420

Source:http://linkedlifedata.com/resource/pubmed/id/1649420

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1991-8-20
pubmed:abstractText
In the present studies, an attempt was made to elucidate the role of endogenous opioid inputs to the depressor region of the caudal ventrolateral medulla in the tonic regulation of arterial pressure and to examine the subtype(s) of receptor underlying any observed effects by use of receptor-specific antagonists. The depressor region of the caudal ventrolateral medulla in chloralose-anesthetized, artificially ventilated rabbits was functionally identified by injection of l-glutamate (5 nmol). Bilateral injection of the non-selective opioid antagonist naloxone (0.3, 5 and 20 nmol) into the caudal ventrolateral medulla produced a dose-dependent depressor response, accompanied by a bradycardia, suggesting a tonically active inhibitory opioid input to this region. Bilateral injection of the selective delta-receptor antagonist ICI 174,864 (0.3 nmol) or of the kappa-receptor antagonist nor-binaltorphimine (1 nmol), also markedly reduced both arterial pressure and heart rate. In contrast, injection of the mu-selective antagonist beta-funaltrexamine (0.3-0.6 nmol) produced no effect on arterial pressure or heart rate. These data support the hypothesis that tonically active endogenous opioid inputs, possibly enkephalinergic and/or dynorphinergic, inhibit the depressor neurones of the caudal ventrolateral medulla in the rabbit through activation of delta- and kappa-receptors. Surprisingly, injection of the opioid agonists leu-enkephalin (1 nmol) or dynorphin 1-13 (0.1 nmol), but not the selective mu-receptor agonist DAGO (1 nmol), in the depressor area of the caudal ventrolateral medulla also induced naloxone-sensitive (5 mg/kg, i.v.) decreases in both arterial pressure and heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0028-3908
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
383-90
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Endogenous opioids tonically inhibit the depressor neurones in the caudal ventrolateral medulla of rabbits: mediation through delta- and kappa-receptors.
pubmed:affiliation
Department of Medicine, Flinders Medical Centre, South Australia.
pubmed:publicationType
Journal Article