1-磷酸鞘氨醇对烧伤后血管通透性的作用研究

目的探讨1-磷酸鞘氨醇（sphingosine 1-phosphate，SIP）对小鼠烧伤后血管通透性的影响。方法BABL／c雄性小鼠，90℃（假烧伤组为37℃）水烫背部体表面积约30％致Ⅲ度烧伤后补液1ml，复制烧伤模型。实验分为6组：假烧伤组、假烧伤＋S1P组、假烧伤4-DMS组、烧伤组、S1P＋烧伤组、烧伤＋S1P组。连续观察小肠系膜微静脉烧伤后20～50min的荧光白蛋白渗出情况，用荧光密度比值Pa表示血管通透性，Pa越大通透性越高。结果假烧伤组4-DMS组Pa值在50min时为0．8160±0．0713，明显高于单纯假烧伤组（0．6575±0．1154，P〈0．05）。烧伤后血管通透性显著增加，S1P＋烧伤组Pa值自烧伤25min后明显低于烧伤组（P〈0．01），维持在正常水平，而烧伤＋S1P组Pa值与烧伤组比较无明显统计学差异。结论S1P对正常的内皮屏障功能具有保护作用。烧伤后血管通透洼显著增加，S1P能预防烧伤后血管通透性的增加，但对烧伤后已经升高的血管通透性没有明显治疗作用。

Effect of Sphingosine 1-phosphate on Vascular Permeability in Scalding Injury

Objective To study the effect of sphingosine 1-phosphate (S1P) on vascular permeabil-ity after burn in mice. Methods A third-degree scald burn was induced in mice on the dorsal skin covering about 30% total body surface area. Animals were resuscitated immediately with 1 ml 0.9% sterile saline intramuscularly. The mice were divided into 6 groups: sham-burn, sham-burn plus S1P, sham-burn plus DMS, burn, S1P plus burn, burn plus S1P. The microcirculation and transvascular flux of albumin were observed in the mice mesentery using intravital fluorescence microscopy from 20 to 50 min after burn. The ratio of the transmural intensity Pa represented the vascular permeability. Results The inhibition of S1P synthesis by DMS significantly in-creased the mesentery venular permeability, while the exogenous S1P did not alter the basal vascular barrier function. The high vascular permeability in burn group was attenuated by administration of S1P before burn injury. But the application of S1P after scalding did not improve the hyperpermeability response. Conclusion S1P might be essential in maintaining the basal vascular barrier function and could be protective in burn insult by preventing the increase of venular permeability.