Baan M, Taverne M A M, de Gier J, Kooistra H S, Kindahl H, Dieleman S J, Okkens A C
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.
Theriogenology. 2008 Mar 1;69(4):399-407. doi: 10.1016/j.theriogenology.2007.10.008. Epub 2007 Dec 3.
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.
为了增进我们对犬分娩相关内分泌变化的理解，我们测定了6只自然分娩母犬和6只在妊娠第58天用孕酮受体阻滞剂阿格列司酮诱导分娩的母犬血浆中孕酮（P4）、15-酮二氢前列腺素F（2α）（PGFM）、雌二醇-17-β（E2β）、皮质醇、促肾上腺皮质激素（ACTH）、催乳素（PRL）、促黄体生成素（LH）和促卵泡生成素（FSH）的浓度。诱导组幼犬的排出发生在P4浓度仍升高的情况下。两组在分娩前PGFM浓度均升高，但诱导分娩的母犬中PGFM水平较低。两组在分娩期间PGFM水平均达到峰值，自然分娩组在分娩后迅速下降，但诱导组仍保持升高。两组中，皮质醇浓度在排出开始前的最后30小时内达到相似的最高水平。产后3天内，诱导组的皮质醇浓度较高。在整个研究过程中，ACTH浓度变化很大，组内和组间均无显著差异。两组中，在妊娠后期至分娩前30小时期间，E2β浓度下降，PRL浓度升高。妊娠后期至产后期间，LH（自然分娩组）和FSH（两组）的浓度均下降。本研究结果说明了母犬分娩前后的激素变化，并揭示与自然分娩的犬相比，阿格列司酮诱导的分娩与黄体溶解仍不完全、PGFM谱改变以及产后皮质醇浓度升高有关。
