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.

中文翻译：

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妊娠早期母猪的孕酮和黄体激素分泌模式。

我们在第11天和第21天研究了授精后备母猪的黄体生成激素（LH）搏动性和黄体（CL）的发作性孕激素释放，目的是建立这两种激素之间的关系。在第11天，第16天和第21天，以15分钟的间隔每隔12小时从腔静脉尾静脉导管中采血。安乐死时，有八头母猪怀孕，六头未怀孕。在第11天，怀孕和未怀孕的后备母猪的孕酮参数（基础，平均，脉搏频率和脉搏振幅）没有差异，LH脉搏频率和振幅趋于不同（p  = .07和p  = .079）。在妊娠小母猪的基础和平均孕酮中，孕酮的脉冲幅度和频率从第11天到第21天显着下降（p <.05）。从第11天到第21天，LH脉冲幅度也显着下降（p  <.05）。在第21天的1小时内，没有LH脉冲跟随有孕激素脉冲。在第11天和第21天，LH脉冲模式出现同步，因为在12小时内有两个或三个LH脉冲，并且这些LH脉冲出现在同一时间窗口。我们得出结论，在小母猪怀孕的第11天和第21天，孕激素脉冲在一个小时内未跟随LH脉冲。进一步地，我们证明了妊娠CL的成功或不成功形成独立于授精后第11天的孕酮释放。我们确认了从第11天到第21天，阴道腔尾静脉中的孕酮水平下降 并且可以证明这种下降部分是由于孕酮脉冲幅度和频率降低，并且该下降与LH脉冲幅度下降同时发生。