Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Saarentaus, Finland.
Adaptation Physiology Group, Department of Animal Sciences, Wageningen University & Research, Wageningen, The Netherlands.
Reprod Domest Anim. 2020 Jul;55(7):795-804. doi: 10.1111/rda.13686. Epub 2020 Jun 5.
We studied luteinizing hormone (LH) pulsatility and episodic progesterone release of the corpus luteum (CL) on Day 11 and Day 21 in inseminated gilts and aimed to establish a relationship between these two hormones. Blood was collected at 15-min intervals for 12 hr on Days 11, 16 and 21 from a vena cava caudalis catheter. At euthanasia, eight gilts were pregnant and six gilts were not pregnant. Progesterone parameters (basal, mean, pulse frequency and pulse amplitude) did not differ between pregnant and non-pregnant gilts on Day 11, LH pulse frequency and amplitude tended to differ (p = .07 and p = .079). In pregnant gilts, basal and mean progesterone, progesterone pulse amplitude and frequency declined significantly from Day 11 to Day 21 (p < .05). A significant decline was also seen in the LH pulse amplitude from Day 11 to Day 21 (p < .05). None of the LH pulses was followed by a progesterone pulse within 1 hr on Day 21. On Day 11 and Day 21 appeared a synchronicity in the LH pulse pattern, as there were two or three LH pulses in 12 hr and these LH pulses appeared in the same time window. We conclude that on Day 11 and Day 21 of pregnancy in gilts, progesterone pulses do not follow an LH pulse within one hour. Further we demonstrated that the successful or not successful formation of a CL of pregnancy is independent of progesterone release on Day 11 after insemination. We confirmed the decline of progesterone from Day 11 to Day 21 in the vena cava caudalis and could demonstrate that this decline is partly due to lower progesterone pulse amplitude and frequency and that the decline occurs simultaneously with a decline in LH pulse amplitude.
我们研究了受精后第 11 天和第 21 天小母猪的促黄体激素（LH）脉冲和黄体（CL）间歇性孕酮释放，并旨在建立这两种激素之间的关系。在受精后第 11 天、第 16 天和第 21 天，通过尾静脉导管每 15 分钟采集血液 12 小时。安乐死后，8 头母猪怀孕，6 头母猪未怀孕。第 11 天，怀孕和未怀孕的小母猪之间孕激素参数（基础值、平均值、脉冲频率和脉冲幅度）没有差异，LH 脉冲频率和幅度有差异的趋势（p=0.07 和 p=0.079）。在怀孕的小母猪中，基础值和平均值、孕酮脉冲幅度和频率从第 11 天到第 21 天显著下降（p<0.05）。第 11 天到第 21 天，LH 脉冲幅度也显著下降（p<0.05）。在第 21 天的 1 小时内，没有一个 LH 脉冲伴随着孕酮脉冲。第 11 天和第 21 天，LH 脉冲模式出现同步性，12 小时内有两个或三个 LH 脉冲，这些 LH 脉冲出现在相同的时间窗口。我们的结论是，在小母猪妊娠的第 11 天和第 21 天，孕酮脉冲不会在一小时内跟随 LH 脉冲。此外，我们证明了妊娠黄体的成功或不成功形成与受精后第 11 天的孕酮释放无关。我们证实了在尾静脉中孕酮从第 11 天到第 21 天的下降，并证明这种下降部分是由于孕酮脉冲幅度和频率降低，并且这种下降与 LH 脉冲幅度的下降同时发生。
