creators_name: Kristal, Mark B. type: journalp datestamp: 1998-11-15 lastmod: 2011-03-11 08:53:43 metadata_visibility: show title: Enhancement of Opioid-Mediated Analgesia: A Solution to the Enigma of Placentophagia ispublished: pub subjects: behav-neuro-sci subjects: bio-ani-behav subjects: bio-behav subjects: bio-etho subjects: bio-evo subjects: bio-theory subjects: comp-psy subjects: neuro-endocrin subjects: neuro-pharm subjects: neuro-physio subjects: physio-psy subjects: psy-bio full_text_status: public keywords: Placenta, POEF, Placentophagia, Amniotic fluid, Parturition, Delivery, Analgesia, Antinociception, Opioids, Morphine, Addiction, Tolerance, Withdrawal, Maternal behavior, Mammals, Afterbirth, Pregnancy, Pain abstract: Two major consequences of placentophagia, the ingestion of afterbirth materials that occurs usually during mammalian parturition, have been uncovered in the past several years. The first is that increased contact, associated with ingesting placenta and amniotic fluid from the surface of the young, causes an accelerated onset of maternal behavior toward those young. The second, which probably has importance for a broader range of mammalian taxa than the first, is that ingestion of afterbirth materials produces enhancement of ongoing opioid-mediated analgesia. The active substance in placenta and amniotic fluid has been named POEF, for Placental Opioid-Enhancing Factor. Recent research on both consequences is summarized, with particular attention to POEF, the generalizability of the enhancement phenomenon, its locus and mode of action, and its significance for new approaches to the management of pain and addiction. date: 1991 date_type: published publication: Neuroscience & Biobehavioral Reviews volume: 15 number: 3 pagerange: 425-435 refereed: TRUE citation: Kristal, Mark B. (1991) Enhancement of Opioid-Mediated Analgesia: A Solution to the Enigma of Placentophagia. [Journal (Paginated)] document_url: http://cogprints.org/180/1/review.html