重症烧伤休克大鼠白细胞表面beta-2整合素的表达

目的 :阐明烧伤休克时 beta-2整合素与白细胞 -内皮细胞粘附间的关系。方法 :将 16只 SD大鼠随机均分为对照组和烧伤休克组。应用流式细胞技术检测中性粒细胞及单细胞表面 beta-2整合素CD11a( LFA-1)和 CD11b( Mac-1)的表达量变化 ,同时比较观察二组动物肠系膜微循环中微静脉内白细胞与内皮细胞粘附数量变化。结果 :二组自身对照 (烫伤前与烫伤后 3 h或开腹前与开腹后 3 h)及相互对比结果显示 ,中性粒细胞及单核细胞表面 CD11a表达量均无显著差异 ( P>0 .0 5 ) ;在烧伤组 ,单核细胞 CD11b有显著降低( P<0 .0 5 ) ,而中性粒细胞 CD11b有显著升高 ( P<0 .0 5 )。微循环观察结果显示 ,休克组动物烫伤后随时程延长附壁滚动及紧密粘附的白细胞数量明显增多 ,而对照组则无明显变化。结论 :烧伤休克状态下 ,白细胞表面 CD11a数量无显著变化 ,而 CD11b数量则有所改变。白细胞 -内皮细胞粘附力的增强可能有 beta-2整合素功能活性上调参与。

Surface Expression of Beta-2 Integrin on Leukocytes in Severe Burn Shock Rats

Objective: To elucidate the relationship between surface expression of beta 2 integrin on leukocytes and leukocyte endothelium adhesion. Methods: 16 SD rats were randomly divided into burn shock group( n =8) and control group( n =8). Surface expressions of LFA 1(CD11a) and Mac 1(CD11b) on granulocytes and monocytes were detected by use of flow cytometry, and the number of leukocytes rolling on and adhere to the venule wall in mesenteric microcirculation was counted. Results: There was no significant change of LFA 1 surface expression on granulocytes and monocytes in both burn shock group and control group( P > 0.05 ). Mac 1 markedly increased on granulocytes but decreased on monocytes in burn shock group( P < 0.05 ). There was significant increase of leukocytes rolling and adhere to the venule wall as the time course prolonged after burn in shock group, but no obvious change was found in control group. Conclusions: Under severe burn shock state, the amount of CD11b(instead of CD11a) on leukocytes surface changed significantly; the functional up regulation of beta 2 integrins may play important role in the enhancement of leukocyte endothelium adherence.