Modifications of ambulation-increasing effect of morphine and buprenorphine following repeated administration in mice.
Interaction of behavioral effects of morphine (10 and 20 mg/kg s. c.) and buprenorphine (0.3 and 1 mg/kg s. c.) were investigated by means of ambulatory activity following repeated administration of either drug in mice. The repeated administration of buprenorphine (1 mg/kg, but not 0.3 mg/kg) total of 5 times at intervals of 3-4 days induced a gradual decrease in the sensitivity to its ambulation-increasing effect. The buprenorphine-experienced mice showed an increase in the sensitivity to the ambulation-increasing effect of morphine (20 mg/kg) in parallel with the doses of buprenorphine. On the other hand, the ambulation-increasing effect of morphine (10 and 20 mg/kg) progressively enhanced during the repeated administration schedule. The morphine-experienced mice demonstrated a decrease in the sensitivity to buprenorphine (1 mg/kg). The present results may reflect differential characteristics between morphine and buprenorphine in their ambulation-increasing effects in mice.
Asahi
T
T
Division for Behavior Analysis, Behavior Research Institute, Gunma University School of Medicine.
Kuribara
H
H
Tadokoro
S
S
D000818:Animals; D002047:Buprenorphine / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004361:Drug Tolerance; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*
D002047:Buprenorphine; D009020:Morphine