氧化铍致大鼠肺损伤与枸杞多糖保护作用实验研究

Experimental research on redox damage induced by beryllium oxide and its protection for lycium barbarum polysaccharide in rats

目的探讨氧化铍(Be O)诱发肺损伤的机制与枸杞多糖(LBP)对Be O致肺损伤的保护作用。方法无特定病原体级健康雄性SD大鼠128只随机分为空白对照组、溶剂对照组、染毒组、干预低剂量组和干预高剂量组。空白对照组不给予任何处理;溶剂对照组采用一次性非暴露式气管内灌注灭菌生理氯化钠溶液0.5 ml;染毒组采用一次性非暴露式气管内灌注质量浓度为10 g/L的Be O溶液0.5 ml,制备Be O肺损伤模型;干预低剂量组和干预高剂量组染毒处理同染毒组,于染毒次日分别以10和40 mg/kg体质量LBP溶液灌胃,1次/d,直至处死。上述5组大鼠分别于实验20、40、60和80 d时间点分批处死,取肺组织采用光学显微镜观察肺组织损伤情况,同时检测肺组织匀浆和肺泡灌洗液中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、一氧化氮合酶(NOS)活力以及丙二醛(MDA)、一氧化氮(NO)水平。空白对照组和溶剂对照组合并为对照组。结果染毒组大鼠肺组织病理学改变基本符合人类慢性铍病的特点。与对照组60和80 d时间点比较,染毒组、干预低剂量组和干预高剂量组相同时间点大鼠肺组织匀浆和肺泡灌洗液中SOD、NOS活力和NO水平均降低,MDA水平均升高(P<0.05)。除干预低剂量组和干预高剂量组60 d时间点肺泡灌洗液外,染毒组、干预低剂量组和干预高剂量组60和80 d时间点大鼠肺组织匀浆和肺泡灌洗液中GSH-Px活力分别高于相同时间点的对照组(P<0.05)。与染毒组80 d时间点比较,干预高剂量组相同时间点大鼠肺组织匀浆和肺泡灌洗液中SOD、NOS活力和NO水平均升高,GSH-Px活力降低(P<0.05)。干预高剂量组60、80 d时间点大鼠肺组织匀浆MDA水平分别低于相同时间点的染毒组和干预低剂量组(P<0.05)。与干预低剂量组80 d时间点比较,干预高剂量组相同时间点大鼠肺泡灌洗液中NOS活力和NO水平均升高,GSH-Px活力降低(P<0.05)。与同组20 d时间点比较,染毒组、干预低剂量组和干预高剂量组60、80 d大鼠肺组织匀浆、肺泡灌洗液中SOD、NOS活力和NO水平均降低,MDA水平和GSH-Px活力均升高(P<0.05)。结论 Be O可引起大鼠肺组织氧化损伤,LBP对Be O导致的肺损伤具有保护作用。

Objective To explore the mechanism of beryllium oxide （BeO） inducing lung damage and the protective effects of lycium barbarum polysaccharide （LBP）. Methods One-hundred and twenty-eight specific pathogen free healthy male SD rats were randomly divided into blank control group, solvent control group, exposure group, and low- and high- dose intervention groups. Blank control group was not given any treatment; solvent control group was iutratracheally injected with 0.5 ml of sterilized normal solution ; exposure group was intratracheally injected with l0 g/L BeO 0.5 ml for preparing the lung injury model; low- and high- dose intervention groups were given LBP by gavage at 10, 40 mg/kg body weight （ once a day, continue till execution） respectively. Optical microscoy was used to observe the injury in lung tissue on day 20, 40, 60 and 80. The activity of superoxide dismutase （ SOD）, glutathione peroxidase （ GSH-Px）, nitric oxide synthase （NOS） and the levels of malondialdehyde （MDA） , nitric oxide （NO） in lung homogenate and bronchoalveolar lavage fluid were measured by kits. The blank control group and solvent control group were merged into control group. Results Pathological changes of the lung tissue of rats in BeO exposure group were similar to the characteristics of chronic beryllium disease in human. Compared with those of the control group on day 60 and 80, the activities of SOD and NOS and the level of NO in the exposure group, low- and high- dose intervention groups in lung homogenate and bronchoalveolar lavage fluid were decreased, while the level of MDA was increased （ P 〈 0.05 ）. Except the low- and high- dose intervention groups on day 60 in bronchoalveolar lavage fluid, the activities of GSH-Px in exposure group, low- and high- dose intervention groups on day 60 and 80 in lung homogenate and bronchoalveolar lavage fluid were increased than those of the control group respectively （ P 〈 0.05 ）. Compared with those of the exposure group on day 80, the activities of SOD, NOS and the level of NO were increased, the activity of GSH-Px was decreased in lung homogenate and bronchoalveolar lavage fluid in hlgh-dose intervention group （P 〈 0.05）. The level of MDA was significantly decreased in lung homogenate than those of exposure group and high-dose intervention group on day 60 and 80 respectively （P 〈 0.05）. Compared with those of the low-dose intervention group on day 80, the activity of NOS and the level of NO were increased, the activity of GSH-Px was decreased in high-dose intervention group （P 〈 0.05）. Compared with the same group on day 20, the activities of SOD and NOS and the level of NO were decreased, the level of MDA and the activity of GSH-Px were increased（P 〈 0. 05 ）. Conclusion BeO can cause oxidative damage of lung tissue in rats, LBP has protective effects on lung injury caused by BeO.