Kus L, Handa R J, McNulty J A
Department of Cell Biology, Neurobiology and Anatomy, Loyola University Stritch School of Medicine, Maywood, IL 60153.
J Pineal Res. 1993 Jan;14(1):39-44. doi: 10.1111/j.1600-079x.1993.tb00483.x.
Glutamate, an excitatory neurotransmitter/neuromodulator involved in cell-to-cell communication within the central nervous system, is now believed to play a role in neuroendocrine function. In this study we describe a single, saturable, stereospecific, and temperature-, time-, and pH-dependent binding site for glutamate in the pineal gland of the rat (Kd = 612 +/- 23 nM, Bmax = 3.17 +/- 0.33 pmol/mg protein). After removal of the sympathetic innervation to the pineal gland, [3H]glutamate binding displayed a higher apparent affinity (Kd = 412 +/- 28 nM) (P < 0.05) without a change in binding site number (Bmax = 3.60 +/- 0.24 pmol/mg protein). No difference in [3H]glutamate binding site number was observed in pineal glands obtained from animals sacrificed during the middle of the light and dark periods. These data suggest a possible modulatory role for a glutamate binding site in pineal gland function.
谷氨酸是一种参与中枢神经系统内细胞间通讯的兴奋性神经递质/神经调质，目前认为它在神经内分泌功能中发挥作用。在本研究中，我们描述了大鼠松果体中一个单一、可饱和、立体特异性且依赖温度、时间和pH的谷氨酸结合位点（解离常数Kd = 612 ± 23 nM，最大结合容量Bmax = 3.17 ± 0.33 pmol/mg蛋白）。去除松果体的交感神经支配后，[3H]谷氨酸结合表现出更高的表观亲和力（Kd = 412 ± 28 nM）（P < 0.05），而结合位点数没有变化（Bmax = 3.60 ± 0.24 pmol/mg蛋白）。在光照期和黑暗期中期处死的动物的松果体中，未观察到[3H]谷氨酸结合位点数的差异。这些数据表明谷氨酸结合位点在松果体功能中可能具有调节作用。
