氨基脲敏感型胺氧化酶介导的甲胺代谢产物对成纤维细胞的毒性作用

目的：研究氨基脲敏感型胺氧化酶（SSAO）催化甲胺（MA）产生的代谢产物对大鼠皮肤成纤维细胞（RSFCs）的毒性作用。方法：原代分离培养新生SDRSFCs，用高效液相色谱法检测细胞及培养基酶活性。MTT法检测细胞经过不同浓度MA和不同活性SSAO处理后的细胞活力，β半乳糖苷酶染色检测细胞衰老。结果：当SSAO为1．02×10^-3u／mL时，成纤维细胞活力随着培养体系中MA浓度的升高（0．2—1．0mmol／L）而降低。当MA为1．0mmol／L时，随着酶活性的增高（0．6×10^-3-1．58×10^-3u／mL），细胞活力逐渐降低。给予SSAO抑制剂氨基脲或肼届嗪可显著抑制细胞活力下降。给予抗氧化剂谷胱苷肽可显著提高细胞活力，并显著降低培养基中甲醛浓度（P〈0．05）；如同时给予过氧化氢酶和谷胱苷肽，则细胞活力升高更明显。此外，0．2mmol／LMA作用3代，可引起肛半乳糖苷酶染色增强。结论：SSAO催化的MA氧化对RSFCs有明显的毒性作用，这种毒性作用由其代谢产物引起；在SSAO催化下低浓度MA可能与细胞衰老有关。

The Toxic Effect of Methylamine Metabolites on the Fibroblasts Mediated by Semicarbazide-sensitive Amine Oxidase

Objective： To investigate the toxic effects of methylamine（MA）metabolites on the rat skin fibroblasts mediated by semicarbazide-sensitive amine oxidase （SSAO）. Methods： SD rat skin fibroblasts were isolated and cultured. High-performance liquid chromatography was performed to determine the SSAO activity in the cells and culture medium. The cells were treated with various concentration of MA or various activity of SSAO. MTT assay was carried out to determine the cell viability, and β-galactosidae staining was performed to detect cell senescence. Results： After treatment with various concentration of MA or various activity of SSAO, the concentration-dependent and activity-dependent decreases in cell viability were observed. SSAO inhibitor（semicarbazide and hydralazine or catalase and tathion）could elevate cell viability. After treatment with 0.2 mmol/L MA for 3 passages, the fibroblasts showed positive staining of β-galactosidae. Conclusion ： The metabolites of MA eatalazed by SSAO are toxic to skin fibroblasts. Low concentration of MA catalyzed by SSAO can be related to cell senescence.