Hormonal changes in spontaneous and aglépristone-induced parturition in dogs.
To increase our understanding of the endocrine changes associated with parturition in dogs, plasma concentrations of progesterone (P4), 15-ketodihydroprostaglandin F(2alpha) (PGFM), estradiol-17-beta (E2beta), cortisol, ACTH, prolactin (PRL), LH, and FSH were measured in six spontaneously whelping bitches and in six bitches in which parturition was induced with the progesterone-receptor blocker aglépristone on day 58 of pregnancy. Expulsion of pups in the induced group took place in the presence of P4 concentrations that were still elevated. PGFM concentrations increased before parturition in both groups, but levels were lower in the induced bitches. PGFM levels reached a maximum in both groups during parturition and quickly decreased in the spontaneously whelping group after parturition, but remained elevated in the induced group. In both groups, cortisol concentrations reached similar maximum levels during the last 30 h before the onset of expulsion. During the 3 days postpartum, cortisol concentrations were higher in the induced group. The highly variable ACTH concentrations did not differ significantly throughout the study within or between groups. In both groups, E2beta concentrations decreased and PRL concentrations increased between the late gestational period and the 30-h period before parturition. Concentrations of both LH (spontaneously whelping group) and FSH (both groups) decreased between late gestation and the postpartum period. The results of this study illustrate the hormonal changes around parturition in the bitch, and reveal that aglépristone-induced parturition is associated with still incomplete luteolysis, an altered PGFM profile, and elevated postpartum cortisol concentrations as compared with spontaneously whelping dogs.
Baan
M
M
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, P.O. Box 80154, NL-3508 TD Utrecht, The Netherlands.
Taverne
M A M
MA
de Gier
J
J
Kooistra
H S
HS
Kindahl
H
H
Dieleman
S J
SJ
Okkens
A C
AC
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D004285:Dogs / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D004963:Estrenes / Q000008:administration & dosage*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006728:Hormones / Q000097:blood*; D006854:Hydrocortisone / Q000097:blood; D007751:Labor, Induced / Q000379:methods / Q000662:veterinary*; D007986:Luteinizing Hormone / Q000097:blood; D036801:Parturition / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood
D004963:Estrenes; D006728:Hormones; C419063:aglepristone; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D004958:Estradiol; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D015237:Dinoprost; D006854:Hydrocortisone