title: Amniotic-fluid ingestion by parturient rats enhances pregnancy-mediated analgesia.
abstract: Amniotic fluid and placenta contain a substance (POEF, for Placental Opioid-Enhancing Factor) that, when ingested, enhances opioid-mediated analgesia in nonpregnant rats; ingestion of the substance by rats not experiencing opioid-mediated analgesia, however, does not produce analgesia. It is highly likely that periparturitional analgesia-enhancement is a significant benefit of ingestion of the afterbirth (placentophagia) during delivery. Here we report that prepartum ingestion of amniotic fluid (via orogastric infusion) does indeed enhance the endogenous-opioid-mediated analgesia evident at the end of pregnancy and during delivery; that the degree of enhancement is greater with 0.75 ml than with 0.25 ml; and that the prepartum enhancement of analgesia can be blocked with the opioid antagonist naloxone.
authors.affiliation: Department of Psychology, State University of New York, Buffalo 14260.
authors.forename: M B
authors.initials: MB
authors.lastname: Kristal
authors.forename: A C
authors.initials: AC
authors.lastname: Thompson
authors.forename: P
authors.initials: P
authors.lastname: Abbott
authors.forename: J M
authors.initials: JM
authors.lastname: Di Pirro
authors.forename: E J
authors.initials: EJ
authors.lastname: Ferguson
authors.forename: J C
authors.initials: JC
authors.lastname: Doerr
mesh_terms: D000653:Amniotic Fluid / Q000502:physiology*; D000698:Analgesia / Q000662:veterinary*; D000704:Analysis of Variance; D000818:Animals; D005260:Female; D007743:Labor, Obstetric / Q000502:physiology; D009270:Naloxone / Q000494:pharmacology; D010147:Pain Measurement / Q000662:veterinary; D049590:Postpartum Period / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D051381:Rats / Q000502:physiology*
chemical_list: D009270:Naloxone