不同粒径纳米和常规微米SiO2对大鼠肺、肝、心、睾丸组织的氧化损伤作用

摘要

目的：探讨不同粒径纳米和常规微米SiO2对大鼠肺、肝、心、睾丸组织的氧化损伤作用。方法采用气管直接滴注法给大鼠染毒，滴注后48 h处死大鼠，测定肺、肝、心、睾丸组织超氧化物歧化酶( SOD )活性、谷胱甘肽过氧化物酶( GSH-Px )活性及脂质过氧化作用(LPO)水平。结果①在67.5 mg/kg剂量下，20 nm SiO2、60 nm SiO2均可引起肺、肝、睾丸组织SOD活性显著降低(P＜0.05)，微米SiO2只引起肺组织SOD酶活性降低(P＜0.05)。各实验组大鼠心脏SOD活性无显著性变化(P＞0.05)。②在67.5 mg/kg剂量下，20 nm SiO2、60 nm SiO2及微米SiO2均可引起肺、肝脏GSH-Px活性显著降低(P＜0.05)，且20 nm SiO2还引起心肌组织GSH-Px活性显著降低(P＜0.05)，微米SiO2只引起肺组织GSH-Px活性降低(P＜0.05)。③20 nm SiO2、60 nm SiO2均可引起肺、肝和睾丸组织LPO水平显著升高(P＜0.05)，且20 nm SiO2还引起心肌组织LPO水平显著升高(P＜0.05)，微米SiO2只引起肺组织LPO水平显著升高(P＜0.05)。结论微米SiO2只引起肺组织的氧化损伤，而20 nm SiO2、60 nm SiO2均可引起肺、肝、心、睾丸组织不同程度的氧化损伤作用，且20 nm SiO2的毒性作用强于60 nm SiO2的毒性作用。%Objective To probe into the oxidative damage effect of SiO2 of nanometer with different grain diameter and conventional mi-crons on rat lung , liver , heart , and testicular tissue . Methods Rats were given direct tracheal instillation for contamination and were put to death after 48 h , then the activities of SOD , GSH-Px , the levels of LPO in lungs , livers , hearts , and testicular tissues of rats were measured . Results ①In 67 . 5 mg/kg dose , 20 nm SiO2 and 60 nm SiO2 caused significant decrease of SOD activities in liver , lung , and testicular tis-sues (P<0.05),but micro-SiO2 caused only decrease of SOD activities in lungs (P<0.05).SOD activities in hearts showed no significant changes(P>0.05).②In 67.5 mg/kg dose,20 nm SiO2,60 nm SiO2,and micro SiO2 caused decrease of GSH-Px activities in livers and lungs (P<0.05),and 20 nm SiO2 also caused decrease of GSH-Px activities in cardiac muscle tissues(P<0.05),but micro SiO2 caused only de-crease of GSH-Px activities in lungs ( P<0 . 05 ) .③20 nm SiO2 , 60 nm SiO2 caused clear increase of the levels of LPO in lungs , livers , and tes-ticular tissues(P<0.05),and 20 nm SiO2 also caused clear increase of the levels of LPO in cardiac muscle tissues(P<0.05),but micro SiO2 caused only clear increase of the levels of LPO in lungs ( P<0 . 05 ) . Conclusion Micro SiO2 only causes oxidative damage to lung tis-sues , but 20 nm SiO2 and 60 nm SiO2 can cause oxidative damage to the lung , liver , heart , and testicular tissues in varying degrees , and the toxic action of 20 nm SiO2 is stronger than that of 60 nm SiO2 .