艾烟可控式动态吸入染毒对大鼠血清中LDL-r、ICAM-1及心脏组织形态的影响

Effects of controllable dynamic inhaled exposure of moxa smoke on LDL-r、ICAM-1and morphology of heart tissue in rats

目的:观察长期暴露于不同浓度艾烟环境下大鼠的脂质代谢、血管内皮及心脏组织形态的变化,为探讨艾烟对心血管系统安全性评价提供参考依据。方法:将168只Wistar大鼠随机分为4组,即空白对照组、低浓度组、中浓度组、高浓度组,每组42只,分别暴露于0%、10%、40%、70%浓度(以染毒柜不透光率度量)的艾烟环境中,每天干预20min,连续干预6个月后取材,采用酶联免疫吸附测定(ELISA)法检测各组大鼠血清中低密度脂蛋白受体(LDL-r)和细胞间黏附因子1(ICAM-1)的含量,用苏木精伊红染色法将心脏组织切片染色后观察不同浓度组大鼠心脏组织形态的改变。结果:(1)低浓度组艾烟干预后,大鼠血清中LDL-r、ICAM-1的含量与空白对照组比较差异均无统计学意义(均P>0.05);中浓度组大鼠艾烟干预后,血清中LDL-r含量显著升高,与空白对照组比较差异有统计学意义(3.87±0.27)mg/mL vs(2.12±0.13)mg/mL,P<0.01),但ICAM-1含量无显著变化;高浓度组大鼠血清中LDL-r含量有上升趋势,但与空白对照组比较差异无统计学意义(P>0.05),ICAM-1含量显著上升(P<0.01)。(2)心脏组织形态改变:光镜下观察各组心肌纤维及心肌细胞均未见异常改变。结论:低浓度艾烟长期干预对大鼠脂质代谢、血管内皮未见显著影响,低浓度艾烟临床使用相对安全;中浓度艾烟长期干预使大鼠胆固醇清除率显著升高,提示艾烟对脂质代谢有良性调节作用;高浓度艾烟对血管内皮有一定损伤,其损伤机制有待于进一步研究;各浓度组艾烟均不造成心脏组织的病理改变。

Objective To observe the change of lipid metabolism and vascular endothelium as well as morphology of heart tissue in rats who were long-time exposed to moxa smoke with different concentrations in order to provide reference for safety assessment of moxa smoke on cardiovascular system. Methods One hundred and sixty-eighty Wistar rats were randomly divided into a control group, a low-concentration group, a median-concentration group and a high-concentration group, 42 rats in each one. The rats were exposed to moxa smoke with concentra- tion of 0%, 10%, 40% and 70%, respectively, for 20 min per day. After continuous intervention for six months, enzyme-linked immunosorbent assay （ELISA） was applied to measure the level of low density lipoprotein-receptor （LDL-r） and intercellular adhesion molecule-1 （ICAM-1） in blood serum in each group; the slices of heart tissue were stained with hematoxylin-eosin staining method to observe morphology change of heart tissue. Results （1） After the intervention of moxa smoke, the levels of LDL-r and ICAM-1 in the low-concentration group were not statistically different from those in the control group （both P〉0.05）; the level of LDL-r in the median-concentration group was significantly increased, which was statistically different from that in the control group [（3.87 ± 0.27） mg/mL vs （2.12±0.13） mg/mL, P〈0. 011, however, the content of ICAM-1 was not obviously changed, although the level of LDL-r in the high-concentration group was presented with an escalating trend, it was not statis- tically different from that in the control group （P〉0.05） while the level of ICAM-1 was obviously increased （P〈 0.01）. （2） Under the light microscope, the abnormalities of cardiac muscle fibers and myocardial cell in each group were not been observed. Conclusion The long-time intervention of low-concentration moxa smoke has no significant effects on lipid metabolism and vascular endothelium of rats, indicating that clinical application of low-concentration moxa smoke is relatively safe. The long-time intervention of moderate-concentration moxa smoke could significantly increase the clearance rate of cholesterol, implying the beneficial regulation of moxa smoke on lipid metabolism. The high-concentration moxa smoke could induce certain damage to vascular endothelium but its mechanism is in need of further research. The pathologic change of heart tissue could not be induced by moxa smoke with any concentration.