title: Opioid peptides and opiates differ in receptor selectivity.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D003917:Dextrorphan / Q000494:pharmacology; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D007536:Isomerism; D007981:Levorphanol / Q000494:pharmacology; D008691:Methadone / Q000494:pharmacology; D009020:Morphine / Q000378:metabolism*; D009270:Naloxone / Q000031:analogs & derivatives*; D009271:Naltrexone / Q000378:metabolism*; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*
chemical_list: D004723:Endorphins; D004745:Enkephalins; D011957:Receptors, Opioid; D003917:Dextrorphan; D007981:Levorphanol; D009270:Naloxone; D009271:Naltrexone; D009020:Morphine; D008691:Methadone