Peripheral morphine analgesia resistant to tolerance in chronic morphine-treated mice.
Intraplantarly (i.pl.)-injected morphine showed a peripheral analgesia in experiments to assess the blockade of bradykinin (i.pl.)-induced nociceptive flexor response in mice. The peripheral morphine analgesia in mice which developed central analgesic tolerance to chronic morphine (10 mg/kg s.c., 5 days), was equivalent to that in vehicle-treated mice in any doses between 0.1 and 1 nmol (i.pl.). These findings suggest that morphine tolerance in the central analgesia may use unique mechanisms deficient in the peripheral nervous system.
Ueda
H
H
Department of Molecular Pharmacology and Neuroscience, Nagasaki University School of Pharmaceutical Sciences, Japan. ueda@net.nagasaki-u.ac.jp
Inoue
M
M
D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000818:Animals; D004361:Drug Tolerance; D007273:Injections, Intramuscular; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000627:therapeutic use*; D013997:Time Factors
D000701:Analgesics, Opioid; D009020:Morphine