Blockade of tolerance to morphine analgesia by pentobarbital.
D000698:Analgesia; D000818:Animals; D004361:Drug Tolerance; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D009020:Morphine; D010424:Pentobarbital