School of Biosciences and Veterinary Medicine, University of Camerino, Matelica, Italy.
Department of Veterinary Medicine, University of Perugia, Perugia, Italy.
Reprod Domest Anim. 2020 Dec;55(12):1794-1802. doi: 10.1111/rda.13846. Epub 2020 Nov 10.
Aglepristone was administered in bitches during the follicular phase to evaluate its effects on progesterone, estradiol-17β and LH serum concentrations. Ten German Shepherds were divided into two groups (treated n = 5; control n = 5). Treated bitches received 10 mg/kg BW of aglepristone subcutaneously during the early follicular phase, 24 hr after and then 7 days later. The control group was injected, at the same time periods, with saline solution (0.3 ml/kg BW). For the steroid evaluations, blood was collected daily from the onset of proestrus until the first day of cytological dioestrus. For LH base-line serum determination, blood was also collected every 20 min for 2 hr at the onset of proestrus. For LH surge identification, blood was collected daily (every 6 hr) starting from the day of the first administration of aglepristone or saline solution until the first day of dioestrus. All animals ovulated but the treated group presented longer ovulation-dioestrus intervals than the control group (5.2 ± 2.2 days p < .05). Serum concentrations of the evaluated hormones were similar between experimental animals except for serum LH. Indeed, no LH peaks were detected in the treated group while LH surges were clearly observed in the control group (9 ± 1 days after the beginning of proestrus. In particular, the area under the curve for LH was significantly lower in treated than control animals (12 ± 4 ng/ml x Day; p = .01). In conclusion, administrations of aglepristone during the follicular phase of the bitch does not affect the steroid hormone patterns but does prevent the occurrence of a LH surge. This work raises significant questions and opens perspectives concerning the mechanisms of ovulation in bitches.
在滤泡期给母犬注射aglepristone，评估其对孕酮、雌二醇-17β 和 LH 血清浓度的影响。10 只德国牧羊犬分为两组（治疗组 n=5；对照组 n=5）。治疗组母犬在滤泡早期，即发情前期 24 小时后和 7 天后，每 10mg/kg BW 皮下注射 aglepristone。对照组同时注射生理盐水（0.3ml/kg BW）。为了评估类固醇，从发情前期开始，每天采集血液，直到细胞学发情期的第一天。为了确定 LH 基础血清值，在发情前期开始时，还每隔 20 分钟采集血液 2 小时。为了确定 LH 激增，从 aglepristone 或生理盐水首次给药的那天开始，每天（每 6 小时）采血，直到发情期的第一天。所有动物都排卵了，但治疗组的排卵发情间隔比对照组长（5.2±2.2 天，p<0.05）。除了 LH 之外，实验组和对照组的血清激素浓度相似。实际上，在治疗组中没有检测到 LH 峰值，而在对照组中清楚地观察到 LH 激增（发情前期开始后 9±1 天）。特别是，治疗组的 LH 曲线下面积明显低于对照组（12±4ng/ml x 天；p=0.01）。总之，在母犬滤泡期给予 aglepristone 不会影响类固醇激素模式，但会阻止 LH 激增的发生。这项工作提出了重要的问题，并为母犬排卵的机制开辟了新的视角。
