Erskine M S, Kornberg E, Cherry J A
Department of Biology, Boston University, MA 02215.
Physiol Behav. 1989 Jan;45(1):33-9. doi: 10.1016/0031-9384(89)90163-7.
When estrous female rats regulate or pace (P) the timing of vaginal intromissions received from males during mating, the stimulation is more effective in inducing luteal function and abbreviating the period of receptivity than is nonpaced (NP) stimulation. The present studies examined whether the coital stimuli necessary for each of these functional consequences are similar. In Experiment 1, estrous females received either 5 or 10 intromissions from males in P or NP tests; control animals received mounts-without-intromission (MO). The duration of estrus was not affected by 5P, 5NP, or 10NP stimulation, but was significantly abbreviated in 10P animals. In contrast, activation of prolonged luteal function occurred in 70% of 5P females compared to only 10% of 5NP females; luteal activation was similar in 10P and 10NP females (74% for both groups combined). In Experiment 2, male copulatory behaviors were compared in tests with P and NP females. Males tested with P females exhibited significantly longer intromission durations (616 +/- 21 msec) than did males tested with NP females (527 +/- 30 msec). Other measures of male copulatory performance such as the number of intromissions to ejaculation and the ejaculation latency did not differ between groups. These studies demonstrate that luteal activation is more readily induced by paced coital stimulation than is abbreviation of estrus. In addition, they suggest that differences between P and NP females in the behavioral and neuroendocrine responses to coital stimulation may result from differences in intromission duration displayed by males under these test conditions.
当处于发情期的雌性大鼠在交配过程中调节或控制（P）从雄性那里接受阴道插入的时间时，这种刺激在诱导黄体功能和缩短接受期方面比无控制（NP）刺激更有效。本研究考察了这些功能结果各自所需的交配刺激是否相似。在实验1中，处于发情期的雌性大鼠在P或NP测试中接受来自雄性的5次或10次插入；对照动物接受无插入的爬跨（MO）。发情期的持续时间不受5P、5NP或10NP刺激的影响，但在接受10P刺激的动物中显著缩短。相比之下，5P组70%的雌性出现了延长的黄体功能激活，而5NP组只有10%；10P组和10NP组雌性的黄体激活情况相似（两组合并为74%）。在实验2中，比较了雄性在与P和NP雌性测试中的交配行为。与NP雌性测试的雄性相比，与P雌性测试的雄性表现出显著更长的插入持续时间（616±21毫秒）。雄性交配表现的其他指标，如插入至射精的次数和射精潜伏期，在两组之间没有差异。这些研究表明，与缩短发情期相比，有节奏的交配刺激更容易诱导黄体激活。此外，它们表明P和NP雌性在对交配刺激的行为和神经内分泌反应上的差异可能源于在这些测试条件下雄性表现出的插入持续时间的差异。
