J.M. DiPirro, M.B. Kristal / Brain Research 1014 (2004) 22-33
31
potent modulatory action on opioid-mediated antinocicep-
tion that is both complex and receptor specific. Placenta
ingestion enhanced antinociceptive activity at the y- and
n-opioid receptor, and suppressed antinociceptive activity
at the A-opioid receptor. These data suggest that a similar
profile of opioid receptor effects is likely induced by
placentophagia during parturition, and point to a number
of significant benefits that may be provided to the
parturient organism by such a receptor-specific pattern,
notably enhancement of pain relief without suppression of
maternal care. Elucidation of the potentially novel mech-
anism of pain modulation involved in POEF action should
provide valuable insight into endogenous systems of
analgesia and aid ongoing efforts to develop improved
therapeutic strategies to manage pain in both humans and
nonhuman animals.
Acknowledgements
Funds used for this research were from NSF Grant IBN-
9123748 awarded to M.B.K., and from funds allocated to
M.B.K. by the Office of the Provost at the University at
Buffalo.
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