TY - GEN ID - cogprints68 UR - http://cogprints.org/68/ A1 - Tarapacki, J. A. A1 - Piech, M. A1 - Kristal, M. B. Y1 - 1995/// N2 - Ingestion of amniotic fluid or placenta by rats has been shown to enhance opioid-mediated analgesia induced by morphine injection, foot shock, vaginal/cervical stimulation, or late pregnancy. The present study was designed to determine whether this mechanism might be a means of providing greater analgesia during the periparturitional period without contributing to the disruption of maternal behavior (measured primarily as retrieval) that can result from excessive opioid levels. Postpartum primiparous rats, injected with either 2 or 3 mg/kg morphine sulfate or vehicle and given orogastric infusions of either amniotic fluid or saline, were tested for maternal behavior. Pain threshold (determined by tail-flick latency test) in rats injected with 2 mg/kg morphine and infused with amniotic fluid was elevated to a level that did not differ significantly from that of a separate group of rats injected with 3 mg/kg morphine and infused with saline. This enhanced analgesia was not, however, accompanied by the significant disruption of maternal behavior found among the rats receiving the higher morphine dose. KW - parturition KW - POEF KW - maternal behavior KW - placentophagia KW - pain KW - antinociception KW - analgesia KW - amniotic fluid KW - opioids KW - morphine KW - pregnancy KW - postpartum KW - tail-flick latency TI - Ingestion of amniotic fluid by postpartum rats enhances morphine antinociception without liability to maternal behavior SP - 209 AV - public EP - 212 ER -