--- abstract: "Ingestion of placenta or amniotic fluid produces a dramatic enhancement of centrally mediated opioid antinociception in the rat. The present experiments investigated the role of each opioid receptor type (m, d, k) in the antinociception-modulating effects of Placental Opioid-Enhancing Factor (POEF—presumably the active substance). Antinociception was measured on a 52 C hotplate in adult, female rats after they ingested placenta or control substance (1.0 g) and after they received an intracerebroventricular injection of a d-specific ([D-Pen2,D-Pen5]enkephalin (DPDPE); 0, 30, 50, 62, or 70 nmol), m-specific ([D-Ala2,N-MePhe4,Gly5-ol]enkephalin (DAMGO); 0, 0.21, 0.29, or 0.39 nmol), or k-specific\r\n(U-62066; spiradoline; 0, 100, 150, or 200 nmol) opioid receptor agonist. The results showed that ingestion of placenta potentiated d- and k-opioid antinociception, but attenuated m-opioid antinociception. This finding of POEF action as both opioid receptor-specific and complex\r\nprovides an important basis for understanding the intrinsic pain-suppression mechanisms that are activated during parturition and modified by placentophagia, and important information for the possible use of POEF as an adjunct to opioids in pain management." altloc: [] chapter: ~ commentary: ~ commref: ~ confdates: ~ conference: ~ confloc: ~ contact_email: ~ creators_id: - '' - kristal@buffalo.edu creators_name: - family: DiPirro given: Jean M. honourific: '' lineage: '' - family: Kristal given: Mark B. honourific: Dr. lineage: '' date: 2004 date_type: published datestamp: 2007-10-22 10:43:55 department: ~ dir: disk0/00/00/57/71 edit_lock_since: ~ edit_lock_until: ~ edit_lock_user: ~ editors_id: [] editors_name: [] eprint_status: archive eprintid: 5771 fileinfo: /style/images/fileicons/application_pdf.png;/5771/1/DiPirro_and_Kristal.pdf full_text_status: public importid: ~ institution: ~ isbn: ~ ispublished: pub issn: ~ item_issues_comment: [] item_issues_count: 0 item_issues_description: [] item_issues_id: [] item_issues_reported_by: [] item_issues_resolved_by: [] item_issues_status: [] item_issues_timestamp: [] item_issues_type: [] keywords: 'placentophagia, POEF, antinociception, opioid, parturition, DPDPE, DAMGO, spiradoline, rat, opioid receptor, delta, kappa, mu, pain' lastmod: 2011-03-11 08:56:59 latitude: ~ longitude: ~ metadata_visibility: show note: ~ number: ~ pagerange: 22-33 pubdom: FALSE publication: Brain Research publisher: Elsevier refereed: TRUE referencetext: ~ relation_type: [] relation_uri: [] reportno: ~ rev_number: 25 series: ~ source: ~ status_changed: 2007-10-22 10:43:55 subjects: - psy-bio - neuro-pharm - behav-neuro-sci succeeds: ~ suggestions: ~ sword_depositor: ~ sword_slug: ~ thesistype: ~ title: 'Placenta ingestion by rats enhances d- and k-opioid antinociception, but suppresses m-opioid antinociception' type: journalp userid: 88 volume: 1014