Abstract
Inhibition of intrathecal substance P-elicited behavior by μ-, δ- and κ-opioids was compared. In both the substance P behavioral test and the tail flick antinociceptive test, intrathecal [D-Ala2,Met5]enkephalinamide and [D-Ala2, D-Leu5]enkephalin (DADL) were equipotent, morphine and ethylketazocine were less potent, but nalorphine was inactive. A long-lasting, highly selective, μ-receptor antagonist, β-funaltrexamine, blocked the inhibition of substance P behaviors by both morphine and ethylketazocine, but did not block the effect of DADL. These results suggest that spinal postsynaptic modulation of nociception is mediated by both δ-type and μ-type opioid agonists.
Original language | English (US) |
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Pages (from-to) | 95-98 |
Number of pages | 4 |
Journal | European Journal of Pharmacology |
Volume | 86 |
Issue number | 1 |
DOIs | |
State | Published - Dec 17 1982 |
Bibliographical note
Funding Information:Supported by USPHS Grants DA01933, T32GM07397 and RR05385. We thank A.E. Takemori for the gift of ~-FNA.
Keywords
- Analgesia
- Intrathecal
- Mice
- Opioids
- Substance P
- δ-Receptors