?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=The+Analgesia-Enhancing+Component+of%0D%0AIngested+Amniotic+Fluid+Does+Not+Affect%0D%0ANicotine-Induced+Antinociception+in%0D%0ANaltrexone-Treated+Rats&rft.creator=ROBINSON-VANDERWERF%2C+T.M.&rft.creator=DiPirro%2C+Jean+M.&rft.creator=Caggiula%2C+Dr.++A.R.&rft.creator=Kristal%2C+Dr.+Mark+B.&rft.subject=Psychobiology&rft.subject=Physiological+Psychology&rft.subject=Behavioral+Neuroscience&rft.subject=Neurochemistry&rft.description=Ingestion+of+amniotic+fluid+and+placenta+by+rats+has+been+shown+to+enhance+opioid-mediated+antinociception+but+not+affect+the+nonopioid-mediated+antinociception+produced+by+aspirin%2C+suggesting+spccificity+for+opioid-mediated+processes.+However%2C+enhancement+by+the+active+substance(s)+in+amniotic+fluid+and+placenta1+(POEF%2C+for+placental+opioid-enhancing+factor)+of+antinociception+produced+by+other+nonopioid+mechanisms+has+yet+to+be+examined.+The+present+experiments+tested+whether+ingestion+of+amniotic+fluid+enhances+the+antinociception+produced+by+nicotine+injection.+In+Experiment+IA%2C+Enhancement+of+morphine-mediated+antinociception+by+ingestion+of+amniotic+fluid+was+demonstrated+in+a+hot-plate+assay.+In+Experiment+IB%2C+rats+pretreated+with+naltrexone+were+given+an+orogastric+infusion+of+amniotic+fluid+or+control+(0.25+ml)%2C+then+injected+with+nicotine+(0%2C+0.075%2C+0.125%2C+or+0.225+mg%2Fkg+subcutaneously)%2C+then+tested+for+antinociception+in+a+hot-plate+assay.+Amniotic+fluid+ingestion+did+not+enhance+the+antinociception+produced+by+various+doses+of+nicotine.+In+Experiment+2%2C+rats+pretreated+with+naltrexone+were+given+an+orogastric+infusion+of+amniotic+fluid+(0%2C+0.125%2C%0D%0A0.25%2C+or+0.50+ml)+and+then+injectcd+with+0.125+mg%2Fkg+nicotine.+None+of+the+doses+of+amniotic+fluid+enhanced+the+nicotine-induced+antinociception.+The+findings+of+these+experiments+lend+support+to+our+contention+that+the+enhancement+by+POEF+of+antinociception+is+specific+to+opioid-mediated+processes.&rft.publisher=Elsevier&rft.date=1997&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F6248%2F1%2Fnicotine.pdf&rft.identifier=++ROBINSON-VANDERWERF%2C+T.M.+and+DiPirro%2C+Jean+M.+and+Caggiula%2C+Dr.+A.R.+and+Kristal%2C+Dr.+Mark+B.++(1997)+The+Analgesia-Enhancing+Component+of+Ingested+Amniotic+Fluid+Does+Not+Affect+Nicotine-Induced+Antinociception+in+Naltrexone-Treated+Rats.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F6248%2F