Abstract
The effects of intraperitoneal (I.P.), intracerebroventricular (ICV) and intrathecal (IT) opiates were studied in the rat neuropathic pain model of Kim and Chung. Dose dependent reduction of allodynia was observed after I.P. and ICV morphine, but not after IT morphine, IT or ICV c[D-pen2 D-pen5]enkephalin (DPDPE) (delta agonist), or IT or ICV U50488H (kappa agonist). The effects of ICV morphine were blocked by I.P. naloxone, but not by IT methysergide, phentolamine or 8-sulfophenyltheophylline. Catalepsy (immobility) was observed after IT, ICV and IT morphine but this was not reliably associated with a reduction of allodynia. I.P. and ICV morphine may thus reduce tactile allodynia via supraspinal, but not spinal, mu opioid receptors.
Publication types
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
-
Analgesics / administration & dosage
-
Analgesics / antagonists & inhibitors
-
Analgesics / pharmacology
-
Analgesics, Opioid / administration & dosage
-
Analgesics, Opioid / pharmacology*
-
Animals
-
Enkephalin, D-Penicillamine (2,5)-
-
Enkephalins / administration & dosage
-
Enkephalins / antagonists & inhibitors
-
Enkephalins / pharmacology
-
Injections, Intraperitoneal
-
Injections, Intraventricular
-
Injections, Spinal
-
Morphine / administration & dosage
-
Morphine / antagonists & inhibitors
-
Morphine / pharmacology
-
Motor Activity / drug effects
-
Naloxone / pharmacology
-
Narcotic Antagonists / pharmacology
-
Pain / drug therapy*
-
Pain / psychology
-
Peripheral Nerve Injuries*
-
Pyrrolidines / administration & dosage
-
Pyrrolidines / antagonists & inhibitors
-
Pyrrolidines / pharmacology
-
Rats
-
Rats, Sprague-Dawley
Substances
-
Analgesics
-
Analgesics, Opioid
-
Enkephalins
-
Narcotic Antagonists
-
Pyrrolidines
-
Naloxone
-
3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
-
Morphine
-
Enkephalin, D-Penicillamine (2,5)-