Rasmussen D D, Malven P V
Neuroendocrinology. 1983 May;36(5):392-6. doi: 10.1159/000123486.
Episodic secretion of luteinizing hormone (LH) in ovariectomized ewes was evaluated before and during acute confinement and during several days of habituation to the same confinement. Plasma concentrations of LH were quantified in samples collected at 5-min intervals via indwelling jugular vein cannulae. Peaks in each time series of plasma LH were identified by a computer program (Pulsar) developed by Merriam and Wachter. In the first experiment, 6 ewes which had been familiarized with the sampling environment and procedures were abruptly moved into a confinement chamber midway through a 4- to 5-hour sampling. Compared with preconfinement sampling, average plasma LH concentrations as well as the incidence (average frequency) and amplitude of identified peaks of LH decreased. In the second experiment, 10 ewes which had not previously been sampled were transferred from their home pens directly into the confinement chamber for a 3- to 4-hour period of blood sampling. This procedure was repeated with the same 10 ewes on the following 2 days to assess the effect of habituation. The average frequency and amplitude of identified peaks of LH increased (p less than 0.05) in habituated ewes, but average plasma LH concentrations did not change. In summary, episodic secretion of LH was inhibited by the stress of initial confinement, but several days of habituation to the same daily periods of confinement minimized this inhibition and restored the episodic discharges of LH.
在切除卵巢的母羊中，对促黄体生成素（LH）的间歇性分泌在急性禁闭前、禁闭期间以及对相同禁闭环境适应数天的过程中进行了评估。通过颈静脉留置套管以5分钟的间隔采集样本，对血浆中LH的浓度进行定量分析。血浆LH每个时间序列中的峰值由Merriam和Wachter开发的计算机程序（Pulsar）识别。在第一个实验中，6只已熟悉采样环境和程序的母羊在4至5小时采样的中途被突然转移到一个禁闭室中。与禁闭前采样相比，血浆LH的平均浓度以及识别出的LH峰值的发生率（平均频率）和幅度均下降。在第二个实验中，10只此前未进行过采样的母羊被直接从其圈舍转移到禁闭室进行3至4小时的采血。在接下来的2天里，对同样的10只母羊重复此操作以评估适应的效果。适应后的母羊中，识别出的LH峰值的平均频率和幅度增加（p小于0.05），但血浆LH的平均浓度没有变化。总之，初始禁闭的应激抑制了LH的间歇性分泌，但对相同每日禁闭时间段的数天适应将这种抑制作用降至最低，并恢复了LH的间歇性释放。
