Evidence for the release of endogenous opiates by morphine.
D000818:Animals; D004723:Endorphins / Q000134:cerebrospinal fluid / Q000378:metabolism*; D051379:Mice; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D011817:Rabbits; D011957:Receptors, Opioid / Q000187:drug effects; D013116:Spinal Cord / Q000502:physiology; D013268:Stimulation, Chemical
D004723:Endorphins; D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine