?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Ingestion+of+Amniotic+Fluid+Enhances%0D%0AOpiate+Analgesia+in+Rats&rft.creator=Kristal%2C+Dr.+Mark+B.&rft.creator=Thompson%2C+Alexis+C.&rft.creator=Abbott%2C+Patricia&rft.subject=Behavioral+Biology&rft.subject=Psychobiology&rft.subject=Physiological+Psychology&rft.subject=Behavioral+Neuroscience&rft.subject=Animal+Behavior&rft.subject=Neurochemistry&rft.description=Placenta+ingestion+has+recently+been+shown+to+enhance+opiate-mediated+analgesia+produced+by+morphine+injection%2C+footshock%2C+or+vaginal%2Fcervical+stimulation.+The+enhancement+of+the+effect+of+endogenous+opiates+(especially+analgesia)+may+be+one+of+the+principal+benefits+to+mammalian+mothers+of+placentophagia+at+delivery.+During+labor+and+delivery%2C+however%2C+mothers+also+ingest+amniotic+fluid+(AF)+which%2C+unlike+placenta%2C+becomes+available+during%2C+or+even+before+expulsion+of+the+infant.+The+present+experiments+were+undertaken+to+determine+(a)+whether+AF+ingestion%2C+too%2C+enhances+analgesia%3B+if+so%2C+(b)+whether+the+effect+requires+ingestion+of%2C+or+merely+exposure+to%2C+AF%3B+(c)+whether+the+effect+can+be+produced+by+AF+delivered+directly+to+the+stomach+by+tube%3B+and+(d)+whether+the+enhancement%2C+if+it+exists%2C+can+be+blocked+by+administering+an+opiate+antagonist.+Nulliparous+Long-Evans+rats+were+tested+for+analgesia+using+tail-flick+latency.+We+found+that+(a)+rats+that+ingested+AF+after+receiving+a+morphine+injection+showed+significantly+more+analgesia+than+did+rats+that+ingested+a+control+substance%3B'+(b)+AF+ingestion%2C+alone%2C+did+not+produce+analgesia%3B+(c)+ingestion+of+AF%2C+rather+than+just+smelling+and+seeing+it%2C+was+necessary+to+produce+analgesia+enhancement%3B+(d)+AF+produced+enhancement%0D%0Awhen+oropharyngeal+factors+were+eliminated+by+delivering+it+through+an+orogastric+tube%3B+and+(e)+treatment+of+the+rats+with+naltrexone+blocked+the+enhancement+of+morphine-induced+analgesia+that+results+from+AF+ingestion.&rft.publisher=Pergamon+Journals+Ltd.&rft.date=1986&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F6252%2F1%2FAF.pdf&rft.identifier=++Kristal%2C+Dr.+Mark+B.+and+Thompson%2C+Alexis+C.+and+Abbott%2C+Patricia++(1986)+Ingestion+of+Amniotic+Fluid+Enhances+Opiate+Analgesia+in+Rats.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F6252%2F