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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1993-11-29
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pubmed:abstractText |
The explanation for the co-existence of opioid and nonopioid components of tramadol-induced antinociception appears to be related to the different, but complementary and interactive, pharmacologies of its enantiomers. The (+) enantiomer had Ki values of only 1.33, 62.4 and 54.0 microM at mu, delta and kappa receptors, respectively. The (-) enantiomer had even lower affinity at the mu and delta sites (Ki = 24.8, 213 and 53.5 microM, respectively. The (+) enantiomer was the most potent inhibitor of serotonin uptake (Ki = 0.53 microM) and the (-) enantiomer was the most potent inhibitor of norepinephrine uptake (Ki = 0.43 microM). Basal serotonin release was preferentially enhanced by the (+) enantiomer and stimulation-evoked norepinephrine release was preferentially enhanced by the (-) enantiomer. The (+) and (-) enantiomers each independently produced centrally mediated antinociception in the acetylcholine-induced abdominal constriction test (ED50 = 14.1 and 35.0 micrograms i.t., respectively). Racemic tramadol was significantly more potent (P < .05) than the theoretical additive effect of the enantiomers (antinociceptive synergy). Synergy was also demonstrated (P < .1) in the mouse 55 degrees C hot-plate test (i.p. route) and (P < .05) the rat Randall-Selitto yeast-induced inflammatory nociception model (i.v. and i.p. routes). Critically, the enantiomers interacted less than synergistically in two side-effects of inhibition of colonic propulsive motility and impairment of rotarod performance. The racemate and the (+) enantiomer were active in a chronic (arthritic) inflammatory pain model. Taken together, these findings provide a rational explanation for the coexistence of dual components to tramadol-induced antinociception and might form the basis for understanding its clinical profile.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Acetylcholine,
http://linkedlifedata.com/resource/pubmed/chemical/Analgesics,
http://linkedlifedata.com/resource/pubmed/chemical/Neurotransmitter Uptake Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Norepinephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Opioid,
http://linkedlifedata.com/resource/pubmed/chemical/Serotonin,
http://linkedlifedata.com/resource/pubmed/chemical/Tramadol
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pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0022-3565
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
267
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
331-40
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:8229760-Acetylcholine,
pubmed-meshheading:8229760-Analgesics,
pubmed-meshheading:8229760-Animals,
pubmed-meshheading:8229760-Arthritis,
pubmed-meshheading:8229760-Drug Synergism,
pubmed-meshheading:8229760-Male,
pubmed-meshheading:8229760-Mice,
pubmed-meshheading:8229760-Mice, Inbred Strains,
pubmed-meshheading:8229760-Neurotransmitter Uptake Inhibitors,
pubmed-meshheading:8229760-Norepinephrine,
pubmed-meshheading:8229760-Pain Threshold,
pubmed-meshheading:8229760-Receptors, Opioid,
pubmed-meshheading:8229760-Serotonin,
pubmed-meshheading:8229760-Stereoisomerism,
pubmed-meshheading:8229760-Structure-Activity Relationship,
pubmed-meshheading:8229760-Tramadol
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pubmed:year |
1993
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pubmed:articleTitle |
Complementary and synergistic antinociceptive interaction between the enantiomers of tramadol.
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pubmed:affiliation |
R. W. Johnson Pharmaceutical Research Institute, Spring House, Pennsylvania.
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pubmed:publicationType |
Journal Article
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