Komitowski D, Muto S, Weiss J, Schmitt B, Taylor G T
Institute for Experimental Pathology, German Cancer Research Center, Heidelberg.
Anat Rec. 1988 Feb;220(2):125-31. doi: 10.1002/ar.1092200203.
Acute, intense sources of "psychogenic" stress clearly modify the structure and function of the hypophysis, and there are concomitant changes in many peripheral physiological systems. Less dramatic sources of stress yield more equivocal results. An experiment is reported in which nuclear morphology of adenohypophyseal cells from 49 male rats exposed to a chronic, low-intensity stressor was examined both by conventional histological and computer-assisted-image-processing methods. The hypothesis tested was that an unequivocal pattern of morphological changes in the nucleus and nuclear chromatin would be revealed by image processing. Rats were killed after living for a year in a relatively low-stress environment, "crowded" in groups of five animals per cage. The control condition was a minimal stress environment of two rats per cage. Results suggested few signs of pathology from peripheral measures of hypophyseal activity, and direct light microscopic examination of the gland revealed no differences between the two groups. Analysis of computer-enhanced images of the pars distalis nuclei from the adenohypophysis, on the other hand, generated findings that were statistically and biologically significant. Nuclear size increased in the stress condition, the number of chromatin and area occupied by the particles increased, and the position of chromatin shifted toward the periphery of the nucleus. Perhaps more important, optical density analysis indicated that chromatin was less tightly packed in the experimental animals. Implications are that chronic, low-intensity stress modulates nuclear structural changes from a dormant to an active state that portend changes in the peripheral systems influenced by the hypophysis.
急性、强烈的“心因性”应激源明显会改变垂体的结构和功能，同时许多外周生理系统也会发生相应变化。不太显著的应激源则会产生更模糊的结果。本文报道了一项实验，通过传统组织学和计算机辅助图像处理方法，对49只暴露于慢性低强度应激源的雄性大鼠腺垂体细胞的核形态进行了检查。所检验的假设是，图像处理将揭示细胞核和核染色质明确的形态变化模式。大鼠在每笼五只动物“拥挤”的相对低应激环境中生活一年后被处死。对照条件是每笼两只大鼠的最小应激环境。结果表明，从垂体活动的外周指标来看，几乎没有病理迹象，对腺体进行直接光学显微镜检查发现两组之间没有差异。另一方面，对腺垂体远侧部细胞核的计算机增强图像分析得出了具有统计学和生物学意义的结果。在应激条件下，细胞核大小增加，染色质数量和颗粒所占面积增加，染色质位置向核周边移动。也许更重要的是，光密度分析表明，实验动物中的染色质包装不那么紧密。这意味着慢性低强度应激会将核结构变化从休眠状态调节到活跃状态，预示着受垂体影响的外周系统会发生变化。
