枪弹压力波损伤内皮细胞的膜信号机制

Signal transduction of pressure wave injured endothelial cells after bullet impact

目的 探讨在投射物侵彻撞击时产生的压力波作用下 ,血管内皮细胞肌醇磷脂信号通路的变化及其在继发损伤中的作用。 方法 以军用 7.6 2mm枪弹侵彻介质水所产生的强压力波作用于培养的血管内皮细胞 ,测定压力波作用后细胞内三磷酸肌醇 (IP3)、游离钙含量以及蛋白激酶C(PKC)、培养液中乳酸脱氢酶 (LDH)活性 ,并以特异的肌醇磷脂代谢阻断剂新霉素预作用于培养内皮细胞后 ,观察压力波作用后上述参数变化。 结果 压力波作用后 2h内IP3明显升高 ,游离钙水平和PKC活性在 4h内显著增加 ,培养液内升高的LDH活性与上述磷酸肌醇代谢激活一致。压力波作用前采用新霉素预作用培养内皮细胞可明显抑制肌醇磷脂代谢激活 ,细胞浆和LDH泄漏。 结论 血管内皮细胞肌醇磷脂信号通路可能是传导投射物侵彻撞击时压力波效应 ,启动继发损伤的重要化学信号通路。

Objective To study the change of phosphoinositide signaling pathway in the vascular endothelial cells exposed to the pressure wave created by bullet impact and its role in the delayed injury of those cells. Methods Temporal pressure wave created by military bullets(7.62 mm in calibre) penetrating water affected the cultured vascular endothelial cells, which was taken as an experimental model in vitro in the present study .The intracellular inositol-1,4,5,-triophosphate(IP 3) , free calcium dynamics,protein kinase C(PKC)activity,which are the paraments of activating phosphoinositide metabolism,were measured after the cultured cells were exposed to the pressure wave. The lactate dehydrogerase(LDH) activity in the cultured mediage were assayed at the same time.To further elucidate the biochemical signaling pathway,cultured cells were pretreated with neomycin,a special blocker for phosphoinositide metabolism,before exposure and the above paraments were assayed after exposure. Results Exposure of the cells to the pressure wave resulted in marked increase of IP 3 within 2h and free calcium and PKC activity within 4h. The increase of LDH leakage from the cells of exposure were parallel with the change of phosphoinositide metabolism.As the cells were pretreated by neomycin before exposure, the activation of phosphoinositide metabolism was suppressed and the LDH leakage weas eliminated in some degrees after exposure. Conclusions The phosphoinositide signaling pathway may be an important component in transduction of pressure wave stimutation into delayed injury to the endothelial cells after projectile penetrating impact.