Abstract
Endogenous inhibitory controls were studied in the spinal nerve ligation model of neuropathic pain. Atipamezole, a selective alpha2-adrenoceptor antagonist, produced both mechanical and cold allodynia in those rats which had not developed clear neuropathic symptoms. The same doses (50 microg i.t. or 1 mg/kg s.c.) did not increase the severity of symptoms in rats which had developed them. The opioid receptor antagonist naloxone (20 microg i.t. or 1 mg/kg s.c.) had no effect on the neuropathic symptoms. These results indicate that mechanical and cold allodynia are under endogenous noradrenergic rather than opioidergic control in this model of neuropathic pain.
Publication types
-
Comparative Study
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adrenergic alpha-Antagonists / pharmacology
-
Animals
-
Disease Models, Animal
-
Imidazoles / pharmacology
-
Ligation
-
Male
-
Naloxone / pharmacology
-
Narcotic Antagonists / pharmacology
-
Norepinephrine / antagonists & inhibitors
-
Norepinephrine / physiology
-
Pain / etiology
-
Pain / physiopathology*
-
Pain Measurement
-
Peripheral Nervous System Diseases / complications*
-
Rats
-
Rats, Sprague-Dawley
-
Receptors, Adrenergic / drug effects
-
Receptors, Adrenergic / physiology*
-
Sodium Chloride / pharmacology
-
Spinal Nerves / drug effects
-
Spinal Nerves / pathology*
-
Spinal Nerves / surgery
Substances
-
Adrenergic alpha-Antagonists
-
Imidazoles
-
Narcotic Antagonists
-
Receptors, Adrenergic
-
atipamezole
-
Naloxone
-
Sodium Chloride
-
Norepinephrine