Linked Life Data

7791108

Source:http://linkedlifedata.com/resource/pubmed/id/7791108

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-7-21
pubmed:abstractText
The developmental changes in mu opiate receptor-mediated antinociception and coupling to guanyl nucleotide binding proteins were studied in the rat. ED50 values for morphine- and sufentanil-induced antinociception were determined in the paw-lift assay on days 10 and 27. The ED50 for morphine analgesia in 10-day-old pups was 0.35 mg/kg and increased with age to 5.3 mg/kg on day 27. Similarly, sufentanil was more potent in pups than in weanlings, the ED50 increasing from 1.7 to 7.6 micrograms/kg. Serum and brain morphine levels after 5 mg/kg of morphine were higher in neonates (day 10) than weanlings (day 27), largely due to a more rapid redistribution phase in weanlings (T1/2 = 26 min.) than in pups (T1/2 = 2.5 hr). Additionally, a substantial (70%) antinociceptive response was achieved in neonates at brain morphine levels that were one-half those producing an equal effect in weanlings. Radioligand binding studies indicated that the number of mu receptors increased 2-fold without change in affinity between days 10 and 27, whereas the GTP analog guanylylimidophosphate was nearly twice as effective in shifting the mu receptors from high to low affinity on day 27 than on day 10. These data indicate that neonatal rats are more sensitive to mu opiate antinociception despite apparently weaker receptor-guanyl nucleotide binding protein coupling. This greater sensitivity is enhanced by the pharmacokinetic differences between neonates and weanlings which result in higher drug levels in pups after a similar dose.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1353-60
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Increased sensitivity to mu opiate antinociception in the neonatal rat despite weaker receptor-guanyl nucleotide binding protein coupling.
pubmed:affiliation
Department of Pharmacology, Duke University Medical Center, Durham, North Carolina, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.