Fabre-Nys C, Martin G B, Venier G
URA CNRS/INRA, Station de Physiologie de la Reproduction, Nouzilly, Monnaie, France.
Horm Behav. 1993 Mar;27(1):108-21. doi: 10.1006/hbeh.1993.1008.
Dose-response relationships have been suggested for the role of estradiol (E2) in the induction of both the LH surge and estrous behavior in the ewe. However, it is not always clear whether it is the amount of E2 or the length of time that E2 is present that is important. Furthermore, in previous studies, the intensity of sexual behavior has rarely been studied quantitatively. Our aims in this work were to analyze in more detail the effects of two injected doses of estradiol benzoate (25 or 50 micrograms) for the induction of both the LH surge and estrous behavior (experiment I) and to dissociate the roles of quantity and duration of presence of E2 as administered by implants (experiment II). Increasing the dose of E2 in both experiment I and experiment II decreased the latency to onset of both the LH surge and the receptivity. The duration of E2 presence marginally affected the latency of both responses and the duration of the LH surge. By contrast, the duration of receptivity depended largely on the duration of E2 presence (experiment II: r = 0.569, P < 0.01). This result explains the dose-duration effect mentioned previously in the literature and found in experiment I. The maximum response increased with dose in both experiment I and experiment II for receptivity and only in experiment I for the LH surge. We conclude that, at estrus, E2 acts in a similar fashion to induce receptive behavior and the LH surge but controls the maximum levels and the duration of these endocrine and behavioral responses differently.
关于雌二醇（E2）在诱导母羊促黄体生成素高峰（LH高峰）和发情行为中的作用，已有人提出剂量-反应关系。然而，E2的量还是E2存在的时间长度起重要作用，这一点并不总是很清楚。此外，在以往的研究中，性行为强度很少进行定量研究。我们这项工作的目的是更详细地分析两种注射剂量的苯甲酸雌二醇（25或50微克）对诱导LH高峰和发情行为的影响（实验I），以及区分植入物给予的E2的量和存在时间的作用（实验II）。在实验I和实验II中增加E2剂量均缩短了LH高峰和接受性开始出现的潜伏期。E2存在的持续时间对两种反应的潜伏期和LH高峰的持续时间有轻微影响。相比之下，接受性的持续时间很大程度上取决于E2存在的持续时间（实验II：r = 0.569，P < 0.01）。这一结果解释了文献中先前提到并在实验I中发现的剂量-持续时间效应。在实验I和实验II中，接受性的最大反应均随剂量增加，而LH高峰仅在实验I中随剂量增加。我们得出结论，在发情期，E2以类似方式诱导接受性行为和LH高峰，但对这些内分泌和行为反应的最大水平和持续时间的控制方式不同。
