?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Enhancement+of+Opioid-Mediated+Analgesia%0D%0Aby+Ingestion+of+Amniotic+Fluid%3A%0D%0AOnset+Latency+and+Duration&rft.creator=Doerr%2C+Jean+C.&rft.creator=Kristal%2C+Dr.+Mark+B.&rft.subject=Psychobiology&rft.subject=Physiological+Psychology&rft.subject=Behavioral+Neuroscience&rft.description=Ingestion+of+placenta+and+amniotic+fluid+has+been+shown+to+enhance+opioid-mediated+analgesia+produced+by+morphine+injection%2C+footshock%2C+vaginal%2Fcervical+stimulation%2C+and+during+late+pregnancy+in+rats.+The+present+study+was+designed+to+determine+how+soon+after+ingestion+the+enhancement+begins+and+how+long+it+lasts.+Tail-flick+latencies+in+Long-Evans+rats+were+determined+before+and+during+vaginal%2Fcervical+stimulation%3B+analgesia+was+measured+as+the+percent+increase+in+tail-flick+latency+during+vaginal+stimulation.+After+determination+of+baseline%2C+rats+were+intubated+with+0.25+ml+of+either+amniotic+fluid+or+beef+bouillon.+We+found+that+analgesia+enhancement+was+detectable+as+early+as+5+minutes+after+ingestion+of+amniotic+fluid%2C+and+the+effect+lasted+at+least+30+minutes%2C+but+no+longer+than+40+minutes.&rft.publisher=Pergamon+Press&rft.date=1989&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F6217%2F1%2Fduration.pdf&rft.identifier=++Doerr%2C+Jean+C.+and+Kristal%2C+Dr.+Mark+B.++(1989)+Enhancement+of+Opioid-Mediated+Analgesia+by+Ingestion+of+Amniotic+Fluid%3A+Onset+Latency+and+Duration.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F6217%2F