Sawashita J, Takeda A, Okada S
Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Brain Res Dev Brain Res. 1997 Sep 20;102(2):295-8. doi: 10.1016/s0165-3806(97)00107-7.
Zinc (Zn) accumulation in the brain of rats of various ages was studied to look into the significance of Zn for the development and function of the brain. The Zn concentration of the cerebral hemisphere was relatively low in 1- to 11-day-old rats. The Zn concentration of the cerebellum gradually increased after birth and reached nearly a plateau at 11 days old. At 48 weeks old, the Zn concentrations of the cerebral cortex and hippocampus formation were approximately twice that of the cerebral hemisphere at the early stage after birth and significantly higher than that of the cerebellum. When 65ZnCl2 was injected into two groups of rats at 5 days and 48 weeks old for comparison, 65Zn distribution in the brain of the former group was higher than that of the latter. In the neonatal rats, the highest concentration of 65Zn was found in the cerebellum, followed by the hippocampus formation, a Zn-containing neuron-rich region. In the adult rats, the highest concentration of 65Zn was found in the CA3 and dentate gyrus of the hippocampus formation. At 48 weeks, 65Zn distribution in the cerebellum was relatively low and at about the same level as in the cerebral cortex. These results suggest that Zn is highly demanded by the cerebellum, which develops rapidly after birth. The increase in Zn concentration with increasing age may reflect the Zn requirement for functioning as an neuromodulator as well as for brain development.
研究了不同年龄大鼠大脑中锌（Zn）的积累情况，以探究锌对大脑发育和功能的重要性。1至11日龄大鼠大脑半球的锌浓度相对较低。小脑的锌浓度在出生后逐渐升高，并在11日龄时几乎达到稳定水平。48周龄时，大脑皮质和海马结构的锌浓度约为出生后早期大脑半球锌浓度的两倍，且显著高于小脑的锌浓度。当分别给5日龄和48周龄的两组大鼠注射65ZnCl2进行比较时，前一组大鼠大脑中的65Zn分布高于后一组。在新生大鼠中，65Zn浓度最高的部位是小脑，其次是海马结构，这是一个富含含锌神经元的区域。在成年大鼠中，65Zn浓度最高的部位是海马结构的CA3和齿状回。48周龄时，小脑的65Zn分布相对较低，与大脑皮质的水平大致相同。这些结果表明，出生后迅速发育的小脑对锌的需求量很大。锌浓度随年龄增长而增加，这可能反映了锌作为神经调节剂以及对大脑发育的需求。
