Gee D M, Flurkey K, Mobbs C V, Sinha Y N, Finch C E
Endocrinology. 1984 Mar;114(3):685-93. doi: 10.1210/endo-114-3-685.
The induction of a LH surge by estradiol (E2) implants was characterized in ovariectomized C57BL/6J mice. Various times after ovariectomy mice were given a priming E2 implant, followed by an LH surge-inducing E2 implant, and were sampled 30 h later at darkness. The magnitude of the E2-induced LH surge was influenced by the postovariectomy interval, sizes of the implants, and age. Mice ovariectomized for 30-60 days before E2 implantation displayed larger surges than those ovariectomized for 4 days. Priming implants yielding 10 pg E2/ml plasma permitted the subsequent induction of vigorous LH surges, whereas no LH surges were observed with slightly larger priming implants that yielded 15 pg E2/ml. The size of the surge-inducing implant was correlated with the size of the subsequent LH surge. However, regardless of implant size, aging mice (8 vs. 13 months old) had smaller LH surges. Sequential daily LH surges were not observed under any conditions, suggesting that mice differ from rats and hamsters in their regulation of LH by E2. Plasma PRL was slightly elevated in the afternoon just before the LH surge, but returned to basal levels during the LH surge, indicating an uncoupling of the LH and PRL surges. The two-stage E2 implantation protocol for inducing LH surges by physiological levels of E2 allows more detailed examination of the priming vs. surge-inducing effects of E2.
在去卵巢的C57BL/6J小鼠中对雌二醇（E2）植入诱导促黄体生成素（LH）峰进行了表征。去卵巢后的不同时间，给小鼠植入启动E2，随后植入诱导LH峰的E2，并在30小时后的黑暗时段进行取样。E2诱导的LH峰的幅度受去卵巢后的间隔时间、植入物大小和年龄的影响。在植入E2前30 - 60天去卵巢的小鼠比4天前去卵巢的小鼠表现出更大的LH峰。产生10 pg E2/ml血浆的启动植入物能够随后诱导强烈的LH峰，而产生15 pg E2/ml的稍大启动植入物则未观察到LH峰。诱导LH峰的植入物大小与随后LH峰的大小相关。然而，无论植入物大小如何，老龄小鼠（8个月与13个月大）的LH峰较小。在任何条件下均未观察到连续每日的LH峰，这表明小鼠在E2对LH的调节方面与大鼠和仓鼠不同。在LH峰即将出现前的下午血浆催乳素（PRL）略有升高，但在LH峰期间恢复到基础水平，表明LH峰和PRL峰解偶联。通过生理水平的E2诱导LH峰的两阶段E2植入方案允许更详细地检查E2的启动作用与诱导作用。
