弱激光照射对早期内毒素血症大鼠肠系膜微循环的影响

Effects of low-level laser irradiation on rat mesenteric microcirculatory disturbance during early stage of endotoxemia

目的 探讨弱激光照射对早期内毒素血症（ETM）大鼠的治疗作用及机制.方法 采用脂多糖（LPS）静脉注射法建立ETM动物模型.60只SD大鼠按随机数字表法分为对照组、LPS组、弱激光照射组,每组20只.照射组在注射LPS 30 min后以SLT型半导体激光治疗仪对大鼠一侧的股动、静脉和耳部血管同时进行照射30 min（波长650 nm、功率5 mW、垂直照射）.在ETM形成1、2、4、6 h后,观察大鼠肠系膜微循环状态,用数字式血流测速仪测定肠系膜微静脉血流速度,激光多普勒血流量图像仪（LDI）测量肠系膜血流量,同时计算肠系膜毛细血管开放数和微循环附壁白细胞数.结果 与对照组比较,LPS组伤后1 h和2 h肠系膜微静脉血流速度（mm/s）增快（1 h：0.190±0.007比0.174±0.009,2 h：0.200±0.010比0.172±0.015,均P＜0.05）,6 h时流速明显减慢（0.116±0.015比0.164±0.011,P＜0.05）;肠系膜血流量及毛细胞血管开放数无明显差异;伤后2、4、6 h白细胞附壁数（个）显著增多（2 h：2.60±1.14比0.40±0.55,4 h：5.40±0.89比0.40±0.55,6 h：5.40±1.52比0.60±0.90,均P＜0.05）;微循环流态发生异常改变,由线流变为粒线流.弱激光照射组肠系膜微静脉血流速度（mm/s）平稳（1、2、4、6 h分别为0.174±0.011、0.180±0.023、0.168±0.013、0.162±0.023）;伤后4 h和6 h白细胞附壁数（个）较LPS组明显减少（4 h：2.00±0.71比5.40±0.89,6 h：2.60±1.52比5.40±1.52,均P＜0.05）,微循环流态改善.结论 弱激光照射可以改善ETM大鼠肠系膜局部微循环,减轻ETM早期的病理损伤.

Objective To observe the effects of low-level laser irradiation on mesenteric microcirculation of rats in vivo in the early stage of endotoxemia （ETM）.Methods The experimental model of ETM was reproduced by injection of lipopolysaccharide （LPS）.Sixty healthy male Sprague-Dawley （SD）rats were divided into three groups used random number table： control group, LPS group and low-level laser irradiation group, each group included 20 rats which were subdivided into four temporal subgroups （1, 2, 4,6 hours, respectively）.In low-level laser irradiation group, the rats were irradiated by type SLT semiconductor laser （650 nm, 5 mW） on unilateral femoral artery and vein, and blood vessel of the ear concurrently for 30 minutes.The interference course was vertical irradiation taken at 30 minutes after the injection of LPS.At 1, 2, 4, 6 hours after the injection of LPS, changes in mesenteric microcirculation and microcirculatory blood flow were recorded with the laser Doppler flowmeter, the velocity of red blood cells in venules was observed, and the number of open capillaries and adherent leukocytes were recorded.Results The blood flow velocity （mm/s） of the mesenteric microcirculation in LPS group was accelerated at 1 hour and 2 hours after LPS injection （1 hour： 0.190± 0.007 vs.0.174 ± 0.009, 2 hours： 0.200± 0.010 vs.0.172±0.015, both P〈0.05, respectively）, but decelerated at 6 hours （0.116±0.015 vs.0.164±0.011,P〈0.05）.The blood flow volume in the mesenteric vessels and the number of open capillaries did not show any significant change at that time.Significant increase in number of adherent leukocytes was observed at 2,4, 6 hours after injury （2 hours： 2.60±1.14 vs.0.40±0.55, 4 hours： 5.40±0.89 vs.0.40±0.55,6hours： 5.40± 1.52 vs.0.60±0.90, all P〈0.05, respectively）.The state of blood flow in the microcirculation became abnormal.After irradiated with laser in low dose, the blood flow velocity was smooth and stable （mm/s, 1 hour： 0.174±0.011, 2 hours： 0.180±0.023, 4 hours： 0.168±0.013,6 hours： 0.162± 0.023）, and the number of adherent leukocytes was reduced significantly at 4 hours and 6hours than that in LPS group （4 hours： 2.00± 0.71 vs.5.40±0.89, 6hours： 2.60 ± 1.52 vs.5.40±1.52, both P〈0.05） and the microcirculatory flow state was improved obviously.Conclusion Low-level laser irradiation may ameliorate the local mesenteric microcirculation, alleviate the microcirculatory disorder in early stage of ETM.