Department of Military Hygiene, Second Military Medical University, Shanghai, China.
Biol Trace Elem Res. 2013 Oct;155(1):65-71. doi: 10.1007/s12011-013-9762-0. Epub 2013 Aug 24.
In humans, long-term exposure to uncontrollable and unpredictable life stressors is a major precipitant in the development of depressive disorders. There are strong evidences that depression is accompanied by lower serum zinc. The aim of present study is to assess the effects of repeated psychological stress (PS) on the zinc metabolism in rat. The rats were divided into control group and PS group which were subdivided into three subgroups: 7-day group, 14-day group, and recovery group (ten rats in each subgroup). PS model was created by a communication box which contains room A and room B. Rats in room A were only exposed to the responses of rats which were randomly given electrical shock for 30 min in room B. PS was given to rats for 30 min every morning for 14 days. The serum corticosterone (CORT), zinc in serum and tissues, and zinc apparent absorption after PS exposure were investigated. The results showed that the serum CORT increased and serum zinc decreased after 7 and 14 days of PS treatment. The zinc concentration in the liver was increased by 14 days PS exposure, whereas its concentration in the hippocampus was decreased by 7 and 14 days of PS exposure. There were no significant changes in zinc concentration in the heart, spleen, kidney, duodenum, cortex, and cerebellum. A decrease in the zinc apparent absorption was observed in the 7- and 14-day PS groups. The increased serum CORT and liver zinc concentrations and decreased serum zinc and apparent absorption of zinc recovered to normal concentrations 7 days away from PS exposure. The results suggest that PS could induce lower serum zinc, which might be correlated with decreased zinc absorption in the small intestine and increased liver zinc accumulation after PS exposure. The consequent effects of decreased hippocampal and serum zinc and increased CORT concentration after PS exposure on stress-related diseases await further research.
在人类中，长期暴露于不可控制和不可预测的生活应激源是抑郁障碍发展的主要诱因。有强有力的证据表明，抑郁伴随着血清锌水平降低。本研究旨在评估重复心理应激（PS）对大鼠锌代谢的影响。将大鼠分为对照组和 PS 组，PS 组又分为 7 天组、14 天组和恢复组（每组 10 只）。PS 模型通过一个包含 A 室和 B 室的交流箱创建。A 室中的大鼠仅暴露于 B 室中随机给予电击的大鼠的反应。每天早上给大鼠 PS 30 分钟，共 14 天。检测 PS 暴露后血清皮质酮（CORT）、血清和组织中的锌以及锌表观吸收率。结果显示，7 天和 14 天 PS 处理后血清 CORT 增加，血清锌降低。14 天 PS 暴露后肝脏锌浓度增加，而海马锌浓度在 7 天和 14 天 PS 暴露后降低。心脏、脾脏、肾脏、十二指肠、皮质和小脑的锌浓度没有明显变化。7 天和 14 天 PS 组锌表观吸收率降低。PS 暴露 7 天后，血清 CORT 和肝脏锌浓度升高，血清锌和锌表观吸收率降低恢复正常。结果表明，PS 可导致血清锌降低，这可能与 PS 后小肠锌吸收减少和肝脏锌蓄积增加有关。PS 暴露后海马和血清锌降低以及 CORT 浓度增加对应激相关疾病的后续影响有待进一步研究。
