二氧化硫吸入对小鼠脑、心、肾、睾丸超微结构的影响

Effects of sulfur dioxide inhalation on ultrastructures of brains, hearts, kidneys and testicles from mice

为了研究二氧化硫(SO2)对小鼠脑、心、肾、睾丸超微结构的影响,以探讨其毒性作用的本质,对小鼠进行SO2动态吸入染毒.设对照组及SO2染毒组(28、56mg·m-3),取各组小鼠脑、心、肾、睾丸于电镜下观察.结果表明:(1)SO2染毒组小鼠脑组织的部分神经元细胞和许多胶质细胞受损,可见胶质细胞核畸形、内质网扩张、线粒体肿胀,以及神经纤维发生髓鞘分离的现象,2种剂量未见明显差异.(2)SO2染毒组小鼠心肌细胞的线粒体肿胀,肌原纤维结构紊乱,细胞核染色质有边集、团块状改变现象,血管内皮细胞肿胀,心肌闰盘扩张、松解;剂量较高的SO2(56mg·m-3)染毒组小鼠,还可见到心肌纤维断裂、溶解,部分心肌细胞肌膜破裂,细胞器释出现象,并可观察到淋巴细胞浸润.(3)SO2染毒组小鼠肾近曲小管上皮细胞受损严重,肾小球和远曲小管上皮细胞也有一定程度的损伤,可见内质网扩张、线粒体肿胀现象;SO2剂量为56mg·m-3的染毒组较剂量为28mg·m-3染毒组更为严重,可见肾小管上皮细胞嗜酸性变、线粒体空泡变现象.(4)SO2染毒可引起小鼠睾丸的基膜、各级生精细胞、精子和支持细胞发生病理改变,可观察到线粒体肿胀、核膜不清、精细胞顶体脱落现象;SO2剂量为56mg·m-3时比剂量为28mg·m-3时超微结构损伤严重,可见基膜破损、细胞器释出现象.本研究为SO2是一种全身性有毒因子的观点提供了病理形态学证据.

To investigate systemic effects of sulfur dioxide inhalation on animals, ultrastructures of brains, hearts, kidneys and testicles were observed with electron microscopy after the mice exposed to SO2 at 28. 00 ± 1.98 and 56. 00 ± 3. 11 mg·m^-3. The results showed ： （ 1 ） For brains, some of the cerebral cortex neurons,many glialcells and nerve fiber were damaged by SO2 ; Nuclear aberrations, increase of endoplasmie retieulum, and mitoehondrial swellings caused by SO2 exposure were observed in these ceils; （2） For hearts, mitochondrial swellings, decreases or disappearances of mitochondria crista, myocardial myofibril disorders, various changes of nucleus and chromatin, intercalated disc dissociations, endothelium edema in heart tissues in both SO2 exposed groups. In addition to above changes, myofibrillar fragmentation and dissolution, myocardial cell membrane breachage and inflammatory cell infiltration were observed in SO2 56 mg·m^-3 group; （3） For kidneys, SO2 exposure exerted serious lesions on ultrastruetures in renal proximal tubular lining cells, meanwhile it damaged glomerulus and distal tubular lining cells; Increases of endoplasmic reticulum and mitochondrial swellings were observed; The changes of 56mg·m^-3 SO2 group were more serious than the 28mg·m^-3 group, decreases and disappearances of mitoehondrial erista were found in 56mg·m^-3 SO2 group;（4） For testicles, compared with control group, the basement membranes, various seminifemus ceils, spermatozoa, sertoli ceils of testicles were changed in both SO2 -exposed groups. The changes caused by SO2 at 56 mg·m^-3 were more serious than the 28 mg·m^-3 SO2 group. These results proved that SO2 might cause uhrastructural changes in multiple organs from mice; it provided pathologic and morphologic evidences for our view that SO2 was a systemictoxic agent.