Amniotic-fluid ingestion by parturient rats enhances pregnancy-mediated analgesia.
Amniotic fluid and placenta contain a substance (POEF, for Placental Opioid-Enhancing Factor) that, when ingested, enhances opioid-mediated analgesia in nonpregnant rats; ingestion of the substance by rats not experiencing opioid-mediated analgesia, however, does not produce analgesia. It is highly likely that periparturitional analgesia-enhancement is a significant benefit of ingestion of the afterbirth (placentophagia) during delivery. Here we report that prepartum ingestion of amniotic fluid (via orogastric infusion) does indeed enhance the endogenous-opioid-mediated analgesia evident at the end of pregnancy and during delivery; that the degree of enhancement is greater with 0.75 ml than with 0.25 ml; and that the prepartum enhancement of analgesia can be blocked with the opioid antagonist naloxone.
Kristal
M B
MB
Department of Psychology, State University of New York, Buffalo 14260.
Thompson
A C
AC
Abbott
P
P
Di Pirro
J M
JM
Ferguson
E J
EJ
Doerr
J C
JC
D000653:Amniotic Fluid / Q000502:physiology*; D000698:Analgesia / Q000662:veterinary*; D000704:Analysis of Variance; D000818:Animals; D005260:Female; D007743:Labor, Obstetric / Q000502:physiology; D009270:Naloxone / Q000494:pharmacology; D010147:Pain Measurement / Q000662:veterinary; D049590:Postpartum Period / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D051381:Rats / Q000502:physiology*
D009270:Naloxone