Linked Life Data

16194531

Source:http://linkedlifedata.com/resource/pubmed/id/16194531

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-11-18
pubmed:abstractText
Neurons in the rostral ventrolateral medulla (RVLM) are involved in both tonic and reflex control of sympathetic outflow. Many of these neurons express the adrenaline-synthesizing enzyme phenylethanolamine N-methyltransferase (PNMT), and are designated C1 neurons. C1 neurons that contain mu-opioid receptors (MORs) are hyperpolarized by MOR activation and are activated during morphine withdrawal. The present study examined the subcellular distribution of the cloned MOR, MOR1, in rat C1 neurons following chronic morphine treatment, using RVLM sections that were dually labeled for PNMT-immunoperoxidase and MOR1-immunogold. Electron microscopic analysis of the subcellular distribution of MOR1 revealed a lower abundance of plasma membrane-associated MOR1 in C1 dendrites of rats treated with morphine, compared to placebo-treated controls, only in distal dendrites. There were no differences in the size of dual-labeled dendrites between treatment groups or in the overall density of MOR1 within PNMT immunoreactive dendrites between treatment groups. These results suggest that chronic morphine treatment leads to a decreased presence of MOR1 at the cell surface, without a significant reduction in cytoplasmic receptor density. These observations suggest that chronic morphine produces a selective internalization of MOR1 in C1 neurons, without apparent changes in receptor synthesis or trafficking. The reduction of accessible MORs on these neurons may be a mechanism for tolerance with regard to autonomic responses to opioid administration and may facilitate the profound sympathetic hyperactivity that occurs during acute opioid withdrawal.
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
196
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
365-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Redistribution of mu-opioid receptors in C1 adrenergic neurons following chronic administration of morphine.
pubmed:affiliation
Department of Neurology and Neuroscience, Weill Medical College of Cornell University, 411 East 69th Street, New York, NY 10021, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural