Geisert Rodney D, Smith Michael F, Schmelzle Amanda L, Green Jonathan A
Division of Animal Sciences, University of Missouri , Columbia, Missouri.
Adv Physiol Educ. 2018 Mar 1;42(1):56-63. doi: 10.1152/advan.00076.2017.
In this teaching laboratory, the students are directed in an exercise that involves designing and performing an experiment to determine estrogen's role in regulating delayed implantation (diapause) in female rats. To encourage active participation by the students, a discussion question is provided before the laboratory exercise in which each student is asked to search the literature and provide written answers to questions and to formulate an experiment to test the role of ovarian estrogen in inducing implantation in female rats. One week before the laboratory exercise, students discuss their answers to the questions with the instructor to develop an experiment to test their hypothesis that estrogen is involved with inducing implantation in the rat. A rat delayed implantation model was established that utilizes an estrogen receptor antagonist (ICI 182,780), which inhibits the action of ovarian estrogens. Groups of mated females are treated with either carrier (control) or ICI 182,780 (ICI) every other day, starting on day 2 postcoitus (pc) until day 8 pc. One-half of the females receiving ICI are injected with estradiol-17β on day 8 pc to induce implantation 4 days after the controls. If the ICI-treated females are not administered estradiol, embryo implantation occurs spontaneously ~4 days after the last ICI injection on day 8. This is a very simple protocol that is very effective and provides an excellent experiment for student discussion on hormone action and the use of agonists and antagonists.
在这个教学实验室中，学生们参与一项练习，该练习包括设计并进行一项实验，以确定雌激素在调节雌性大鼠延迟着床（滞育）中的作用。为鼓励学生积极参与，在实验练习前提供了一个讨论问题，要求每个学生查阅文献，书面回答问题，并设计一个实验来测试卵巢雌激素在诱导雌性大鼠着床中的作用。在实验练习前一周，学生们与教师讨论他们对问题的答案，以制定一个实验来检验他们关于雌激素参与诱导大鼠着床的假设。建立了一个大鼠延迟着床模型，该模型使用雌激素受体拮抗剂（ICI 182,780），它能抑制卵巢雌激素的作用。从交配后第2天（pc）开始，每隔一天给交配后的雌鼠组分别注射载体（对照）或ICI 182,780（ICI），直到交配后第8天。在交配后第8天，给接受ICI处理的雌鼠中的一半注射17β-雌二醇，以在对照后4天诱导着床。如果不给接受ICI处理的雌鼠注射雌二醇，胚胎着床会在第8天最后一次注射ICI后约4天自发发生。这是一个非常简单但非常有效的方案，为学生讨论激素作用以及激动剂和拮抗剂的使用提供了一个很好的实验。
