【摘要】 人疱疹病毒（HVH,0.2 ml/mouse ip）加重谷氨酸单钠(MSG,2.5 g·kg^-1sc)对下丘脑弓状核的损毁,同时,下丘脑和脊髓的线粒体膜结合钙明显降低。Fura-2单细胞检测表明,MSG既可引起胞外Ca₂₊内流,又可促进胞内钙库释放Ca²⁺,使胞内Ca²⁺超载,最终导致细胞死亡。结果提示,MSG可引起胞内Ca²⁺超载而破坏神经元排空或封存Ca²⁺的能力,从而损伤细胞。而HVH可增强上述损伤效应。更多还原

【Abstract】 The neurotoxic effects of sodium glutamate ( MSG , 2 . 5 g · kg-1 sc ) and the enhancing effects of neurotropic Herpesvirus hominis (HVH, 0.2 ml/mouse ip) on MSG toxicity were studied through histomor-phological observations, together with detection of the concentration of both mitochondrial protein bound Ca2+ and intracellular free Ca2+ ([Ca2+]i) by the Tb3+ fluorescent probe and Ca2+ indicator Fura-2/AM, respectively. It was found that in 10-d-old mice the neurons inda-arcuate hypothalamic nucleus degenerated severely after treatment with HVH + MSG, showing swollen edematous cytoplasm, dark pyknotic nuclei as well as a decrease in the amount of the neurons. The hypothalamic and spinal cord mitochondrial Tb3+ relative fluorescent intensity increased, from 20 ± 3 and 20 ± 1 to 28 ± 5 and 34 ± 6, ie, the mitochondrial protein bound Ca2+ reduced significantly. MSG elevated the [Ca2+]i levels from 0. 11 ± 0. 03 to 0. 69 ± 0. 19 μmol·L-1 by not only stimulating the Ca2+ influx but also releasing the Ca2± from intracellular stores. These findings suggested that MSG neurotoxi-city was probably related to the overloading of neuroplasmic Ca2+, the destruction of neu-ronal abilities to deplete or sequester the intracellular Ca2+ , as well as the irreversible neuronal injury and death.更多还原