Servatius R J, Ottenweller J E, Gross J L, Natelson B H
Neurobehavioral Unit, DVA Medical Center, East Orange, NJ 07018.
Physiol Behav. 1993 Jun;53(6):1101-4. doi: 10.1016/0031-9384(93)90365-m.
Typically, stress-related elevations in rat plasma cholesterol (CHOL) require preexposure to diets high in fats or cholesterol and lengthy stressor protocols. We report on two studies in which we measured plasma CHOL 22-h poststressor in rats fed Purina Laboratory Rodent Chow and exposed to 3 (3-day) or 1 (1-day) daily stressor sessions [40, 2 mA tailshocks]. In the first study, both the 3-day and 1-day groups exhibited moderately elevated morning plasma CHOL 22-h poststressor compared to nonshocked controls. Along with the groups in the first study, a second study included a restricted food control, rats transferred to the stressor environment, and rats simply transferred to an adjacent room. Neither restricted feeding nor the room transfers had an effect on morning plasma CHOL. However, the 3-day and 1-day groups again exhibited moderately elevated CHOL. Previous reports did not find elevated plasma CHOL in rats given a single stressor exposure when sampled at the end of the stressor session. Thus, the persistently elevated morning CHOL exhibited by the 1-day group may develop over time. The relatively slow development of plasma CHOL elevations may be related to the time course of stressor-induced thyroid suppression.
通常情况下，大鼠血浆胆固醇（CHOL）与应激相关的升高需要预先暴露于高脂肪或高胆固醇饮食以及长时间的应激源方案中。我们报告了两项研究，在这两项研究中，我们测量了喂食普瑞纳实验用啮齿动物饲料的大鼠在应激源作用后22小时的血浆CHOL，并使其每天接受3次（为期3天）或1次（为期1天）应激源刺激[40次，2毫安尾部电击]。在第一项研究中，与未受电击的对照组相比，3天组和1天组在应激源作用后22小时早晨的血浆CHOL均有中度升高。与第一项研究中的组一起，第二项研究包括一个食物限制对照组、转移到应激源环境的大鼠以及仅仅转移到相邻房间的大鼠。食物限制和房间转移对早晨血浆CHOL均无影响。然而，3天组和1天组的CHOL再次出现中度升高。以前的报告发现在应激源刺激结束时采样，单次暴露于应激源的大鼠血浆CHOL并未升高。因此，1天组持续升高的早晨CHOL可能会随着时间的推移而出现。血浆CHOL升高的相对缓慢发展可能与应激源诱导的甲状腺抑制的时间进程有关。
