Eutheria Foundation, Cross Plains, WI 53528, USA.
Domest Anim Endocrinol. 2011 Aug;41(2):98-109. doi: 10.1016/j.domaniend.2011.05.003. Epub 2011 Jun 12.
Various doses of estradiol-17β (E(2)) were used in heifers to induce a pulse of 13,14-dihydro-15-keto-prostaglandin F(2α) (PGFM). The effect of E(2) concentration on the prominence of PGFM pulses and the relationship between prominence and intrapulse concentration of progesterone (P(4)), LH, and luteal blood flow were studied. A single dose of 0 (vehicle), 0.01, 0.05, or 0.1 mg of E(2) was given (n = six/group) 14 d after ovulation. Blood samples were collected, and luteal blood flow was evaluated hourly for 10 h after the treatment. The 0.05-mg dose increased and the 0.1-mg dose further increased the prominence of the induced PGFM pulse, compared with the 0.0-mg dose and the 0.01-mg dose. The PGFM pulses were subdivided into three different prominence categories (<50, 50 to 150, and >150 pg/mL at the peak). In the 50 to 150 category, P(4) concentration increased (P < 0.05) between -2 h and 0 h (0 h = peak of PGFM pulse). In the >150 category, P(4) decreased (P < 0.05) between -1 h and 0 h, LH increased (P < 0.05) at 1 h, and luteal blood flow apparently decreased (P < 0.05) at 2 h of the PGFM pulse. The novel results supported the following hypotheses: (1) an increase in E(2) concentration increases the prominence of a PGFM pulse, and (2) greater prominence of a PGFM pulse is associated with a greater transient intrapulse depression of P(4) at the peak of the PGFM pulse. In addition, the extent of the effect of prostaglandin F(2α) on the increase in LH and changes in blood flow within the hours of a PGFM pulse was related positively to the prominence of the PGFM pulse.
各种剂量的雌二醇-17β（E(2)）被用于小母牛中，以诱导 13,14-二氢-15-酮-前列腺素 F(2α)（PGFM）的脉冲。研究了 E(2)浓度对 PGFM 脉冲突出度的影响，以及突出度与脉冲内孕酮（P(4)）、LH 和黄体血流之间的关系。排卵后 14 天，小母牛单次给予 0（载体）、0.01、0.05 或 0.1mg 的 E(2)（每组 6 只）。处理后 10 小时内每小时采集血液样本，并评估黄体血流。与 0.0-mg 剂量和 0.01-mg 剂量相比，0.05-mg 剂量增加，0.1-mg 剂量进一步增加了诱导的 PGFM 脉冲的突出度。PGFM 脉冲分为三个不同的突出度类别（<50、50-150 和>150pg/mL 在峰值）。在 50-150 类别中，P(4)浓度在-2 小时至 0 小时（0 小时=PGFM 脉冲峰值）之间增加（P<0.05）。在>150 类别中，P(4)在-1 小时至 0 小时之间减少（P<0.05），LH 在 1 小时增加（P<0.05），并且在 PGFM 脉冲的 2 小时时黄体血流明显减少（P<0.05）。新的结果支持以下假设：（1）E(2)浓度的增加会增加 PGFM 脉冲的突出度，（2）PGFM 脉冲的突出度越大，PGFM 脉冲峰值时 P(4)的瞬时脉冲内抑制越大。此外，PGFM 脉冲内前列腺素 F(2α)对 LH 增加和血流变化的影响程度与 PGFM 脉冲的突出度呈正相关。
