青蒿琥酯对中暑内毒素血症小鼠腹腔巨噬细胞内游离钙浓度的影响

Effects of artesunate on free calcium concentration in peritoneal macrophages of endotoxemia mice induced by hyperthermia

目的 建立高温诱导的内源性内毒素血症的动物模型,研究青蒿琥酯对中暑内毒素血症小鼠腹腔巨噬细胞内游离钙离子([Ca2 + ]i)浓度的影响。方法 昆明小鼠被随机分为常温组、高温组、青蒿琥酯+高温组[连续5d按60mg/(kg·d)腹腔注射给药]。高温组和青蒿琥酯+高温组的小鼠均在干球温度(Tdb) (3 5±0 .5 )℃、相对湿度(RH) (65±5 ) %条件下热暴露2h ,诱导其产生内毒素血症;常温组在干球温度(2 5±0 . 5 )℃、相对湿度(4 3±5 ) %条件下暴露2h。之后立即分离各组腹腔巨噬细胞,采用Fluo 3 /AM负载及流式细胞仪检测细胞内游离[Ca2 + ]i浓度。结果 常温组、高温组和青蒿琥酯+高温组的巨噬细胞内游离[Ca2 + ]i浓度分别为3 . 3 0±0 . 3 4、14 . 2 6±0 . 89和5 . 19±0 . 2 1;高温组较常温组巨噬细胞游离[Ca2 + ]i浓度显著增加(P <0 . 0 1) ,青蒿琥酯+高温组虽高于常温组(P <0 . 0 5 ) ,但明显低于高温组(P <0 . 0 1)。结论 高温诱导小鼠产生内毒素血症时,腹腔巨噬细胞内游离[Ca2 + ]i浓度升高明显,青蒿琥酯则能显著降低细胞内的游离[Ca2 + ]i水平,这可能是其抗内毒素血症、降低机体对内毒素反应、保护细胞的机制之一。

Objective To investigate the effects of artesunate on free calcium ions([Ca 2+]i)concentration in peritoneal macrophages of endotoxemia murine model induced by hyperthermia.Method Kunming mice(6 weeks)were randomly divided into control group,hyperthermia group and artesunate+hyperthermia group[ip with artesunate by a dosage of 60 mg/(kg·d) for 5 days].Endotoxemia was induced by two hours heat exposure,Tdb is(35±0.5)℃ and RH is(65±5)%,in hyperthermia group and artesunate+hyperthermia group.Control group was exposed two hours with Tdb(25±0.5)℃ and RH(43±5)%,and peritoneal macrophages of three groups were isolated immediately.Intracellular free[Ca 2+]i concentration was quantitated directly by a flow cytometer through fluorescent Ca 2+ indicator Fluo-3/AM.Result The free[Ca 2+]i concentrations in peritoneal macrophages of control group,hyperthermia group and artesunate+hyperthermia group were 3.30±0.34、14.26±0.89 and 5.19±0.21 respectively.Compared with control group,intracellular free[Ca 2+]i concentration of hyperthermia group was significantly increased(P<0.01).Artesunate+hyperthermia group's free[Ca 2+]i concentration was higher than that of control group(P<0.05),but markedly lower than that of hyperthermia group (P<0.01).Conclusion Free[Ca 2+]i concentration in peritoneal macrophages of endotoxemia mouse model was strikingly increased induced by hyperthermia.However,artesunate can significantly reduce the level of intracellular free [Ca 2+]i.It may be one of the mechanisms that artesunate can inhibit endotoxemia,reduce reaction of body to LPS and protect cells.