硒对自由基损伤的红细胞引起微循环紊乱的保护作用──动物实验及临床研究

AN ANIMAL EXPERIMENT AND CLINICAL INVESTIGATION ON THE PROTECTIVE EFFECT OF SELENIUM ON THE MICROCIRCULATIC ON INDUCED BY FREE RADICAL DAMAGED RBCs

为研究硒保护实验动物大脑表面微循环免受自由基损伤红细胞的干扰作用、以及术前服硒对心脏手术病人在体外循环过程中皮肤和肌肉微循环的保护效果，在动物实验中利用荧光标记的图象分析法观察大鼠脑微小动静脉直径、流速和通透性的改变，并在临床观察中用激光多普乐法对服硒组心脏手术病人皮肤和肌肉微循环的变化与对照组进行比较研究。结果表明：尽管硒不能改善已受自由基损伤红细胞的变形性，但硒与受自由基损伤的红细胞同时输入不仅可有效防止这些红细胞引起的大鼠脑微小动、静脉直径的缩小、流速的下降和通透性的增大，同时还可适度提高微动脉的流速；服硒使病人术前皮肤升温后最大微循环灌注量与此时皮肤平均微循环灌注量的比值较对照组显著增加（服硒组增加3．95倍，对照组增加1．74倍，P＜0．05），术中自由基产生水平降低、红细胞膜分子流动性和红细胞变形性无特征性改变，但与对照组的皮肤和肌肉微循环变化趋势相同；服硒组术后24h的皮肤平均微循环灌注量几乎回复到术前水平，肌肉微循环恢复不明显。结论：（1）自由基损伤的红细胞可造成微循环明显恶化，（2）微量元素硒可有效地防止受自由基损伤的红细胞对微循环的影响，（3）术前服硒可提高病人术前皮肤微循环的最大灌注量、防止术中红细胞?

Fluorescent labeling image analysis was used to evaluate the changes in cerebral arteriole and veitilet diameters (D), circulation velocities (FV) and Permeability (VP) in rats; While in clinics, a laser-doppler device was used for assessing changes of skins and muscules dricrocirculation. The results show that in control rats, equal volume perfusion of free radical damaged RBCs resulted in decreases of D and FV significantly but VP was increased, Whereas in the case when free radical damaged RBCs were perfused together with selenium, no disturbances in the D and VP were observed with FV even improved. In the humen control coup, either average skin dricrocireulative perfusions (ASMP) at 25T or maximal skin dricrocirculative perfusions (MSMP) at42℃ were evidently decreased during myocaldial ischedria/reperfusion period, while ASMP at 24th hour of post-surgery was kept reducing. At the same time, the changes in muscles ndcrocirculative Perfusions (MMP) tended to be similar to the skin, hut overloaded than the pre-surgery levels at 24th hour of post-surgery Period. In the selenium coup before surgery, the ratio of MSMP to ASMP was obviously increased than the controlgroup (3.95 in Se group us 1.74 in coneal group, P < 0.05), but did not have significantly differences in ASMP, MSMP and MMP between the twO groups during surgery period. RBC deformabilities were not changed. At 24th hour post-surgery, the ASMP were almost restored to pre-surgery levels. However, MMP were still lower than the pre-surgery levels. Conclusions: (1) free radical d^ed RBC perfusion leads to danmge of whcrocirculation; (2 ) selenium is highly efficient in protecting ndcrocirculation from free radical damaged RBC disturbance; and (3 ) Orall adrinistration of selenium may improve pre-surgery maximal skin whcrocirculative perfusion and promote recovery of the worsened skin dricrocirculation in addition to prevent the occurrence of RBC deformability.