Eutheria Foundation, Cross Plains, Wisconsin, USA.
Theriogenology. 2013 Apr 15;79(7):1110-9. doi: 10.1016/j.theriogenology.2013.02.003.
On Day 16 (Day 0 = ovulation) or before the expected transition into the luteolytic period, heifers were not treated (control group, N = 7) or were treated with a single 0.1-mg dose of estradiol (E2) (E2 group, N = 6) or E2 combined with the GnRH antagonist acyline (E2/Ac group, N = 5). Hourly blood samples were collected from hour of treatment (Hour 0) to Hour 20. Estradiol induced a pulse of PGFM, but the peak of the pulse occurred 2 hours later (P < 0.05) and mean PGFM concentrations during the descending portion of the pulse were lower (P < 0.05) in the E2/Ac group than in the E2 group. In the E2 group, concentration of progesterone (P4) decreased (P < 0.05) during the ascending portion of the PGFM pulse, and increased (rebounded; P < 0.05) along with an LH increase during the descending portion. In the E2/Ac group, a rebound in P4 and an increase in LH were not detected during the descending portion of the PGFM pulse. The percentage of CL with color Doppler signals of blood flow increased (P < 0.04) concurrently with the PGFM increase during Hours 0 to 5 and during the ascending portion of the PGFM pulse. Blood flow and PGFM decreased concurrently. The following hypotheses were supported: (1) LH has a positive effect on PGFM pulses; (2) the rebound in P4 and the increase in LH during the descending portion of a PGFM pulse are functionally related; and (3) the increase in luteal blood flow in association with a PGFM pulse represents a direct effect of PGF2α rather than an effect of P4 or LH.
在第 16 天（第 0 天=排卵）或预期进入溶黄体期之前，牛未接受治疗（对照组，N=7）或接受单次 0.1mg 剂量的雌二醇（E2）（E2 组，N=6）或 E2 联合 GnRH 拮抗剂 acyline（E2/Ac 组，N=5）治疗。从治疗时（小时 0）到小时 20 每小时采集血液样本。雌二醇诱导 PGFM 脉冲，但脉冲的峰值晚 2 小时出现（P<0.05），E2/Ac 组脉冲下降期的平均 PGFM 浓度较低（P<0.05）。在 E2 组中，PGFM 脉冲上升期孕酮（P4）浓度降低（P<0.05），随着 PGFM 下降期 LH 增加而增加（反弹；P<0.05）。在 E2/Ac 组中，PGFM 脉冲下降期未检测到 P4 反弹和 LH 增加。与 PGFM 增加同时，具有血流彩色多普勒信号的 CL 百分比增加（P<0.04），在 0 至 5 小时和 PGFM 脉冲上升期期间。血流和 PGFM 同时减少。支持以下假设：（1）LH 对 PGFM 脉冲有积极影响；（2）PGFM 脉冲下降期 P4 反弹和 LH 增加在功能上相关；（3）与 PGFM 脉冲相关的黄体血流增加代表 PGF2α 的直接作用，而不是 P4 或 LH 的作用。
