Time-dependent disruptive effects of apomorphine and alpha-methyl-p-tyrosine on development of morphine tolerance.
In rats the development of one-trial tolerance to the analgesic action of i.p. administered morphine is disrupted by the postadministration of apomorphine (30 mg/kg at 5 min but not at 3 h) or alpha-methyl-p-tyrosine (200 mg/kg at 5 min and 3 h but not at 12 h). Diethyldithiocarbamate or propranol has no disruptive effect. It is suggested that development of tolerance to the analgesic effects of morphine is mediated by sequential time-dependent biochemical processes.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D004050:Ditiocarb / Q000494:pharmacology; D004361:Drug Tolerance; D005260:Female; D006220:Haloperidol / Q000494:pharmacology; D008781:Methyltyrosines / Q000494:pharmacology*; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
D008781:Methyltyrosines; D009020:Morphine; D004050:Ditiocarb; D006220:Haloperidol; D001058:Apomorphine