TY - GEN ID - cogprints6211 UR - http://cogprints.org/6211/ A1 - DiPirro, Jean M. A1 - Thompson, Alexis C. A1 - Kristal, Dr. Mark B. Y1 - 1991/// N2 - Amniotic fluid and placenta contain a substance (POEF) that when ingested enhances opioid-mediated analgesia produced by several agents (morphine injection, vaginal/cervical stimulation, late pregnancy, footshock), but not that produced by aspirin injection. The present series of experiments employed quaternary naltrexone, an opioid antagonist that does not readily cross the blood-brain barrier, in conjunction with either peripheral or central administration of morphine, to determine whether amniotic-fluid ingestion (and therefore POEF ingestion) enhances opioid-mediated analgesia by affecting the central and/or peripheral actions of morphine. The results suggest that POEF affects only the central analgesic effects of morphine. PB - Pergamon Press KW - POEF KW - analgesia KW - pain KW - rats KW - morphine KW - opioids KW - placenta KW - quaternary naltrexone KW - amniotic fluid KW - placentophagia KW - naltrexone methobromide TI - Amniotic-Fluid Ingestion Enhances the Central Analgesic Effect of Morphine SP - 851 AV - public EP - 855 ER -