Rycerz Karol, Krawczyk Aleksandra, Jaworska-Adamu Jadwiga, Arciszewski Marcin B
Department of Animal Anatomy and Histology, Faculty of Veterinary Medicine, University of Life Sciences, Akademicka 12, 20-033 Lublin, Poland.
Biomedicines. 2024 Dec 4;12(12):2763. doi: 10.3390/biomedicines12122763.
Background Monosodium glutamate (MSG) in its anionic form, glutamate, is one of the main excitatory amino acids. Excess of this neurotransmitter may lead to excitotoxicity affecting neurons and astrocytes responsible for glutamate metabolism in different brain areas of animals. The aim of the study was to investigate the immunoreactivity of glial fibrillary acidic protein (GFAP) and S100β protein in the caudate nucleus of rats under the condition of elevated glutamate levels.
Fifteen rats were divided into a control group receiving saline and MSG2 and MSG4 groups receiving 2 g/kg b.w. MSG and 4 g/kg b.w. MSG, respectively, for 3 days. An immunohistochemical reaction was conducted on frontal sections containing the caudate nucleus with use of antibodies against GFAP and S100β.
Analyses indicated elevated density of astrocytes immunoreactive for the studied proteins in the caudate nucleus in animals receiving MSG. The studied glial cells also demonstrated increased immunostaining intensity for both GFAP and S100β immunoreactive cells especially in the MSG4 group. The number of GFAP-positive processes in astrocytes was similar in all studied groups.
The studies demonstrate a potential response of astrocytes to the effect of MSG administration in the caudate nucleus. It was shown that GFAP- and S100β-positive astrocytes in the caudate nucleus may act differently, suggesting distinct roles of these proteins against glutamate excitotoxicity.
背景 谷氨酸单钠（MSG）以其阴离子形式谷氨酸，是主要的兴奋性氨基酸之一。这种神经递质过量可能导致兴奋性毒性，影响动物不同脑区中负责谷氨酸代谢的神经元和星形胶质细胞。本研究的目的是调查谷氨酸水平升高条件下大鼠尾状核中胶质纤维酸性蛋白（GFAP）和S100β蛋白的免疫反应性。
将15只大鼠分为对照组，给予生理盐水，以及MSG2组和MSG4组，分别给予2 g/kg体重的MSG和4 g/kg体重的MSG，持续3天。使用针对GFAP和S100β的抗体，对含有尾状核的额叶切片进行免疫组织化学反应。
分析表明，接受MSG的动物尾状核中对所研究蛋白质免疫反应阳性的星形胶质细胞密度升高。所研究的胶质细胞对GFAP和S100β免疫反应阳性细胞的免疫染色强度也增加，尤其是在MSG4组。所有研究组中星形胶质细胞中GFAP阳性突起的数量相似。
研究表明星形胶质细胞对尾状核中MSG给药的影响有潜在反应。结果表明，尾状核中GFAP和S100β阳性星形胶质细胞的作用可能不同，提示这些蛋白质在对抗谷氨酸兴奋性毒性方面有不同作用。
