Carnosine protects against NMDA-induced neurotoxicity in differentiated rat PC12 cells through carnosine-histidine-histamine pathway and H₁/H₃ receptors

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• 作者：Yao Shen ; Wei-wei Hu ; Yan-yin Fan ; Hai-bing Dai ; Qiu-li Fu ; Er-Qing Wei ; Jian-hong Luo ; Zhong Chen
• 关键词：Carnosine ; Histamine ; Neuroprotection ; Neurotoxicity ; N-methyl-d-aspartate
• 刊名：Biochemical Pharmacology
• 出版年：2007
• 出版时间：1 March 2007
• 年：2007
• 卷：73
• 期：5
• 页码：709-717
• 全文大小：406 K

文摘

Since the histidine-containing dipeptide carnosine (β-alanyl-l-histidine) is believed to have many physiological functions in the brain, we investigated the neuroprotective effects of carnosine and its mechanisms of action in an in vitro model of neurotoxicity induced by N-methyl-d-aspartate (NMDA) in differentiated PC12 cells. Pretreatment with carnosine increased the viability and decreased the number of apoptotic and necrotic cells measured by MTT and Hoechst 33342 and propidium iodide (PI) double staining assays. Carnosine also can inhibite the glutamate release and increase HDC activity and the intracellular and extracellular contents of carnosine, histidine and histamine detected by high-performance liquid chromatography (HPLC). The protection by carnosine was reversed by α- fluoromethylhistidine, a selective and irreversible inhibitor of histidine decarboxylase (HDC). Pyrilamine and thioperamide, selective central histamine H₁ and H₃ antagonists also significantly reversed the protection of carnosine. Further, the inhibition of glutamate release by carnosine was reversed by thioperamide. Therefore, the protective mechanism of carnosine may not only involve the carnosine-histidine-histamine pathway, but also H₁/H₃ receptors and the effective inhibition of glutamate release. This study indicates that carnosine may be an endogenous protective factor and calls for its further study as a new antiexcitotoxic agent.