Plasma levels of cortisol and oxytocin, and uterine activity after cervical artificial insemination in the ewe.
The objective was to compare in the ewe the effects of easy and difficult procedures for artificial insemination (AI) (as related to rapid or poor accessibility of the cervix, respectively) on plasma cortisol (CORT) and oxytocin (OT), and uterine motility. All AI were simulated using a catheter empty of semen to study genital and environmental stimuli only. In experiment 1, 40 ewes were sampled after Al, and whether it was an easy or difficult procedure was reported for each animal. While CORT concentrations rose to a similar amount in all ewes, whatever the Al procedure, a significant OT response occurred after a difficult procedure only (n = 18) (17.4 +/- 1.7 versus 12.7 +/- 0.7 pg x mL(-1) before Al, p < 0.05). In experiment 2, uterine activity was monitored in 4 ewes using an implantable telemetric transmitter equipped with an intrauterine pressure catheter. An increased uterine activity occurred during 2 +/- 1 min after an easy Al (n = 5), whereas the evoked activity lasted for 15 +/- 4 min after a difficult Al (p < 0.001, n = 7). A similar long-lasting response occurred after OT administration (100 mIU, i.v.). We concluded that the increase in uterine motility after a difficult Al resulted from a reflex release of OT, and not to a "stress" effect.
Houdeau
Eric
E
Laboratoire de Neurobiologie des Fonctions Végétatives, INRA, Jouy-en-Josas, France. houdeau@jouy.inra.fr
Raynal
Pierre
P
Marnet
Pierr-Guy
PG
Germain
Guy
G
Mormède
Pierre
P
Rossano
Bernadette
B
Monnerie
Régine
R
Prud'homme
Marie-Jeanne
MJ
D000818:Animals; D004973:Estrus Synchronization; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D007315:Insemination, Artificial / Q000662:veterinary*; D010121:Oxytocin / Q000097:blood*; D012756:Sheep / Q000097:blood* / Q000502:physiology; D013686:Telemetry / Q000379:methods / Q000662:veterinary; D013997:Time Factors; D014599:Uterus / Q000502:physiology*
D010121:Oxytocin; D006854:Hydrocortisone