Development of a new model to investigate the fetal nociceptive pathways.
OBJECTIVE
The aim of the study was to develop an experimental model to investigate the fetal nociceptive pathways and fetal analgesia.


METHODS
We tested the electromyographic (EMG) response from the biceps femoris to electrical stimulation of the sural nerve in chronically-prepared fetal lambs with and without sufentanil.


RESULTS
An EMG response could be recorded 140 ms after the electrical stimulation above a threshold of current's intensity. The response presents the characteristics of a nociceptive flexion reflex. The reflex magnitude increased with the stimulus intensity. Sufentanil decreased the response. Bradycardia was noted 10 s after the stimulation and was not observed after sufentanilinfusion. Catecholamine concentrations were not altered by the stimulation.


CONCLUSIONS
Our study shows that a nociceptive flexion reflex can be recorded in the ovine fetus. We suggest that this reflex can be used as a new tool to study the ontogenesis of the nociceptive pathways and the effects of analgesic drugs during fetal life.
Houfflin Debarge
Véronique
V
Department of Obstetrics, Centre Hospitalier Régional Universitaire de Lille, Lille, France. v-houfflin-debarge@chru-lille.fr
Bresson
Sophie
S
Jaillard
Sophie
S
Elbaz
Frédéric
F
Riou
Yvon
Y
Dalmas
Serge
S
Deruelle
Philippe
P
Ducloy
Anne Sophie
AS
Puech
Francis
F
Storme
Laurent
L
D000698:Analgesia; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D004576:Electromyography; D005260:Female; D005333:Fetus / Q000502:physiology*; D006340:Heart Rate, Fetal; D023421:Models, Animal; D009619:Nociceptors / Q000502:physiology*; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D012018:Reflex / Q000187:drug effects / Q000502:physiology; D012756:Sheep; D017409:Sufentanil / Q000494:pharmacology
D000701:Analgesics, Opioid; D017409:Sufentanil