Placental opioid-enhancing factor (POEF): generalizability of effects.
A substance in amniotic fluid and placenta (POEF for Placental Opioid-Enhancing Factor) has been shown to enhance opiate- or opioid-mediated analgesia in rats. Recent studies have only touched on the generalizability of the phenomenon. The present studies further tested the generalizability of the POEF effect: they examined sex specificity of the mechanism; whether POEF activity exists in afterbirth material of species other than the rat; whether POEF activity exists in tissue other than afterbirth material; whether POEF activity could be demonstrated after injection rather than ingestion of afterbirth material; and whether POEF enhances all opioid-mediated phenomena. We found that (a) POEF is effective in male rats as well as in female rats; (b) POEF activity exists in human and dolphin afterbirth material; (c) ingestion of pregnant-rat liver does not produce enhancement of opioid-mediated analgesia; (d) POEF does not seem to be effective when amniotic fluid is injected either IP or SC; and (e) POEF does not modify morphine-induced hyperthermia.
Abbott
P
P
Department of Psychology, State University of New York, Buffalo 14260.
Thompson
A C
AC
Ferguson
E J
EJ
Doerr
J C
JC
Tarapacki
J A
JA
Kostyniak
P J
PJ
Syracuse
J A
JA
Cartonia
D M
DM
Kristal
M B
MB
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects; D004289:Dolphins; D004723:Endorphins / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects*; D011257:Pregnancy Proteins / Q000494:pharmacology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects; D011957:Receptors, Opioid / Q000187:drug effects*; D012684:Sensory Thresholds / Q000187:drug effects; D013045:Species Specificity
D004723:Endorphins; D011257:Pregnancy Proteins; D011957:Receptors, Opioid; D009020:Morphine