Further studies on the development of tolerance to the analgesic effect of morphine.
D000818:Animals; D004361:Drug Tolerance; D006358:Hot Temperature; D007279:Injections, Subcutaneous; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
D009020:Morphine