@misc{cogprints6254, volume = {36}, number = {6}, author = {Dr. Mark B. Kristal and Alexis C. Thompson and Steve B. Heller and Dr. Barry R. Komisaruk}, title = {Placenta Ingestion Enhances Analgesia Produced by Vaginal/Cervical Stimulation in Rats}, publisher = {Pergamon Press}, journal = {Physiology \& Behavior}, pages = {1017--1020}, year = {1986}, keywords = {Placenta, Pain, Opiates, Vaginal stimulation-produced analgesia, Tail-flick test, Afterbirth, Analgesia, Parturition, Placentophagia, VSPA, Vaginal/cervical stimulation, POEF}, url = {http://cogprints.org/6254/}, abstract = {Ingestion of placenta has previously been shown to enhance opiate-mediated analgesia (measured as tail-flick latency) induced either by morphine injection or by footshock. The present study was designed to test whether placenta ingestion would enhance the partly opiate-mediated analgesia produced by vaginal/cervical stimulation. Nulliparous Sprague-Dawley rats were tested for analgesia, using tail-flick latency, during and after vaginal/cervical stimulation; the tests for vaginal/cervical stimulation-induced analgesia were administered both before and after the rats ate placenta or ground beef. Placenta ingestion, but not beef ingestion. significantly heightened vaginal/cervical stimulation-induced analgesia. A subsequent morphine injection provided evidence that, as in a previous report, placenta ingestion, but not beef ingestion, enhanced morphine-induced analgesia.} }