目的 探讨低剂量组蛋白在脓毒症等感染性疾病中对内皮细胞的作用特征。 方法 以实验室体外表达纯化 的重组人源化组蛋白H3/H4复合物纯品代替小牛胸腺组蛋白，对内皮细胞进行低剂量（10 µg/mL）、长时间（48 h）处理。 观察细胞形态和活性，流式细胞术检测活细胞百分比，检测细胞上清组蛋白含量。 结果 低剂量组蛋白长时间处理可引起 内皮细胞发生持续的细胞死亡，细胞形态变化和功能丧失。这一毒性作用在10 µg/mL组蛋白H3/H4处理时得到重复，且 定量结果显示其在短时间内即可作用于细胞内部引起一系列胞内反应。 结论 比以往实验处理条件更低和更接近于病理 情况的10 µg/mL的H3/H4就能有效引起脓毒症等重症感染性疾病的体内毒性作用。

Objective To investigate the effects of low dose of extracellular histone on endothelial cells in infectious diseases such as sepsis. Methods The endothelial cells were treated with 10 µg/mL recombinant human histone H3/H4 complex in replacement of calf thymus histones (CTH) for various periods of time, and the morphology changes and the viability of the endothelial cells were recorded. In addition, flow cytometry was applied to identify the characteristics of endothelial cells and enzyme-linked immunosorbnent assay (ELISA) was used to detect the extracellular histones level in endothelial cells culture. Results The low dose of CTH could continuously induce endothelial cells death, cell morphological changes and function loss, which was reproduced by 10 µg/mL recombinant histone H3/H4 complex. Results of histones quantitation showed that histone can cause a series of intracellular reactions in a short period of time. Conclusions It is showed that 10 µg/mL H3/H4 can induce the toxicity in infectious disease and this level of the dose is a lower than those used in previous studies and more close to the pathological conditions.