Takeda A, Minami A, Takefuta S, Tochigi M, Oku N
Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
J Neurosci Res. 2001 Mar 1;63(5):447-52. doi: 10.1002/1097-4547(20010301)63:5<447::AID-JNR1040>3.0.CO;2-C.
Zinc concentration and (65)Zn uptake in the brain of rats fed zinc-deficient diet for 12 weeks were examined, based on a previous finding of the impairment of learning behavior by the zinc deprivation. Zinc concentrations in the brain, except for the hippocampal formation, did not decrease significantly in zinc-deficient rats, whereas zinc concentration in the liver of the zinc-deficient rats was approximately half that of control rats. When zinc-deficient rats were subjected to brain autoradiography with (65)Zn, (65)Zn concentration in any brain region of zinc-deficient rats was significantly higher than in control rats 6 days after injection of (65)ZnCl(2). The increase rate of (65)Zn concentration in the brain by the zinc deprivation was approximately 150%, and was similar to those in the liver and serum, suggesting that dietary zinc deprivation may cause a scarcity of zinc in the brain, in addition to the peripheral tissues such as the liver. These results indicate that the adult brain is responsive to dietary zinc deprivation. In the brain of zinc-deficient rats, the increase rate of (65)Zn concentration in the hippocampal formation seemed to be low compared to those in other brain regions. The hippocampal formation may be the most responsive to dietary zinc deprivation in the adult brain. The present finding demonstrates that zinc homeostasis in the brain is altered by chronically dietary zinc deprivation.
基于先前关于锌缺乏会损害学习行为的研究发现，对喂食缺锌饮食12周的大鼠大脑中的锌浓度和（65）锌摄取情况进行了检测。缺锌大鼠大脑中除海马结构外，锌浓度并未显著降低，而缺锌大鼠肝脏中的锌浓度约为对照大鼠的一半。当对缺锌大鼠进行（65）锌脑放射自显影时，注射（65）氯化锌6天后，缺锌大鼠任何脑区的（65）锌浓度均显著高于对照大鼠。锌缺乏导致大脑中（65）锌浓度的增加率约为150%，与肝脏和血清中的增加率相似，这表明饮食锌缺乏除了会导致肝脏等外周组织缺锌外，还可能导致大脑缺锌。这些结果表明，成年大脑对饮食锌缺乏有反应。在缺锌大鼠的大脑中，海马结构中（65）锌浓度的增加率似乎低于其他脑区。海马结构可能是成年大脑中对饮食锌缺乏最敏感的部位。目前的研究结果表明，长期饮食锌缺乏会改变大脑中的锌稳态。
