Abstract
Writhing responses to intraperitoneal acetic acid administration and their modulation by mu-, kappa- and delta-opioid receptor agonists were compared in wild-type and mu-opioid receptor knockout mice. Unpretreated homozygous knockout mice displayed less writhing than wild-type mice. U-50,488 [trans-3,4-dichloro-N-methyl-N-[2-(1-pyrolidinyl)cyclohexyl]-benze neacetamide]) reduced writhing responses in wild-type and knockouts. Morphine and SNC80 [(+)-4-[9-alpha-R)-alpha-(2S,5RO-4-allyl-2,5-dimethyl-1-piperaziny l)-3-methoxybenzyl]-N,N-diethylbenzamide] were effective in wild-type mice but ineffective in knockouts. Mu-opioid receptors appear to play important roles in responses to this visceral nociceptive stimulus and its modulation by mu- and delta-opioid receptor agonists.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer / pharmacology
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Abdominal Pain / metabolism*
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Abdominal Pain / physiopathology
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Abdominal Pain / prevention & control
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Analgesics, Non-Narcotic / pharmacology
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Analgesics, Opioid / pharmacology
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Animals
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Benzamides / pharmacology
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Female
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Male
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Mice
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Mice, Knockout
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Morphine / pharmacology
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Pain Measurement / drug effects
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Piperazines / pharmacology
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Receptors, Opioid, delta / agonists
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Receptors, Opioid, kappa / agonists
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Receptors, Opioid, mu / genetics
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Receptors, Opioid, mu / metabolism*
Substances
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Analgesics, Non-Narcotic
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Analgesics, Opioid
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Benzamides
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Piperazines
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Receptors, Opioid, delta
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Receptors, Opioid, kappa
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Receptors, Opioid, mu
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4-(alpha-(4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl)-N,N-diethylbenzamide
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3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
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Morphine