缺氧条件下冻伤对大鼠微循环血液灌流量的影响

EFFECT OF FROSTBITE UNDER HYPOXIA ON MICROCIRCULATORY PERFUSION IN RATS

本文采用体重２００±２０ｇ健康雄性Ｗｉｓｔａｒ大鼠，随机分为平原冻伤（ＦＮ）组、急性缺氧冻伤（ＦＡＨ）组和缺氧习服缺氧冻伤（ＦＨＡＣ）组，实验观察了大鼠右后肢重度冻伤前后各组大鼠双后肢皮肤微循环灌流量的改变。结果表明，平原冻伤使大鼠双后肢微循环灌流量明显减少，提示局部重度冻伤对微循环的影响不只局限于冻区也涉及到对侧肢体。冷冻前ＦＡＨ组大鼠微循环灌流量已明显低于ＦＮ组，表明急性缺氧时血容量进行代偿性的再分配，使微循环灌流量减少；ＦＡＨ组大鼠冻后双后肢微循环灌流量的改变结果提示急性缺氧可加重其冻伤对微循环的损伤程度。ＦＨＡＣ组大鼠冻前微循环灌流量非常明显地低于正常对照，也明显低于急性缺氧对照，表明缺氧习服可造成微循环障碍；ＦＨＡＣ组大鼠冻肢微循环灌流量非常明显地低于ＦＮ组，提示缺氧习服加重高原冻伤引起的微循环障碍。

Changes of microcirculatory perfusion in rats following cold injury of right hind leg under hypoxia were investigated.Male Wistar rats weighing 200±20g were randomly divided into three groups:frostbite at normoxia (FN) group;frostbite during acute hypoxia (4h at 6000m simulated altitude,FAH) group and frostbite during hypoxia after acclimation (exposure to hypoxia at 6000m,4h daily for 4 weeks,FHAC) group.The results showed that the microcirculatory perfusion of both hind legs decreased markedly in FN after cold injury.It suggests that the frostbite damage can affect microcirculatory perfusion of another leg besides the region of frostbite.The fall of microcirculatory perfusion before freezing in FAH group indicated that there was a compensatory blood redistribution during acute hypoxia.The changes of microcirculatory perfusion in FAH group post freezing indicated that acute hypoxia can aggravate the frostbite damage.The microcirculatory perfusion of FHAC group pre freezing was significantly lower than that of FN and FAH group,and after freezing the perfusion of frostbitten leg in FHAC group was significantly lower than that in FN group,suggesting that hypoxia acclimation may cause disturbance of microcirculation and worsen the frostbite damage at high altitude.