The evaluation of organ injuries due to surgical stress using green fluorescent protein induced rat.

活化的中性粒细胞滞留在肺微血管中，在急性肺损伤中起重要作用。然而，由于在体真实的实时观察PMN在肺微血管中的分布一直是困难的，因此，我们利用绿色荧光蛋白转基因大鼠建立了一种新的方法。将大鼠麻醉、通气，并将导管置于上级腔静脉和主动脉根中，用于给药药剂和监测血压。打开左前外侧胸壁，稳定左肺，在荧光显微镜下观察具有GFP的PMN。用CCD摄像机拍摄图像并记录在硬盘记录器中，对照组（n=4）注射生理盐水。脂多糖（LPS）治疗组注射大肠杆菌LPS（1 mg/kg）。LPS组PMN计数从2610±580个/μl降至1180±220个/μl，P<0.05，而对照组PMN计数无明显变化（2490±700个/μl降至3320±960个/μl）。两组的收缩压和心率均无变化（LPS组：121±9至123± 8 mmHg，319±19至295±20/min;对照组：133±27至135±30 mmHg，322±22至292±22/min）。LPS处理使PMN通过毛细血管的速度从421±86 μm/sec降低到51±21 μm/sec，并增加了毛细血管中的隔离PMN。毛细血管后微静脉中滚动的白细胞数量小于10%，LPS处理不增加PMN的滚动。内毒素血症使PMN通过毛细血管的速度降低，使PMN在毛细血管内的滞留增加，但不改变毛细血管后微静脉内白细胞的滚动。我们进一步评估了一氧化氮和磷酸二酯酶4型抑制剂对肺微循环中PMN隔离的影响。

Activated PMN sequester in pulmonary microvessels and play an important role in acute lung injury. However, the site of PMN sequestration is still controversial, as in vivo real time observation of PMN in pulmonary microvessels has been difficult.We developed a new method using GFP transgenic rat. Rats were anesthetized, ventilated and catheters were placed in the superior vena cava and the aortic root for the administration of agents and the monitoring of blood pressure. The left anterolateral chest wall was opened, the left lung was stabilized and PMN with GFP was viewed under a fluorescent microscope. The image was obtained with CCD camera and recorded in a hard disk recorder.Control group (n=4) received the injection of saline. Lipopolysaccaride(LPS) treated group received the injection of LPS (1mg/kg) from Escherichia coli. PMN count decreased in LPS treated group (2610±580 to 1180±220/μl, p<0.05), while PMN count did not change in control (2490±700 to 3320±960/μl). Systolic blood pressure and heart rate did not change in both groups (LPS;121±9 to 123±8mmHg, 319±19 to 295±20/min, control;133±27 to 135±30 mmHg,322±22 to 292±22/min). LPS treatment decreased PMN velocity passing through capillaries from 421±86 to 51±21 μm/sec and increased sequestered PMN in capillaries. The population of rolling leukocytes in postcapillary venule was less than 10 % and LPS treatment did not increase rolling of PMN. Endotoxemia decreased PMN velocity passing through capillaries and increased PMN sequestration in capillaries, but did not change rolling of leukocyte in postcapillary venule. We further evaluated the effect of nitric oxide and phosphodiesterase type 4 inhibitor on PMN sequestration in pulmonary microcirculation.