title: [Comparative study of nanosized and microsized silicon dioxide on spermatogenesis function of male rats].
abstract: OBJECTIVE
  To compare the effects of nanosized and microsized silicon dioxide on spermatogenesis function of male rats exposed by inhalation.
  
  
  METHODS
  45 male rats were randomly divided into control group and four experimental groups which were exposed by 100 mg/m3 or 300 mg/m3 nanosized and microsized silicon dioxide in inhalation chambers 2 hours every other day. Age-matched rats were exposed to room air with the same condition and served as controls. 65 days later, the testicular and epididymal viscera coefficients, the quantity and quality of sperm were examined and the histopathological assessment was done. The changes in biochemical parameters in serum and testes were also measured.
  
  
  RESULTS
  Nanosized silicon dioxide could induce histopathological changes of testes in rats, and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could reduce the sperm counts of rats and the testicular LDH-C4 activities, increase MDA levels in the testes and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could lead to the reduction of sperm motility, testicular LDH-C4 activities and 8-hydroxydeoxyguanosine (8-OHdG) concentration in serum elevation in particles-exposed rats compared with the control animals, but there are no significant difference compared with that of microsized particles at the same concentration.
  
  
  CONCLUSIONS
  The present findings suggest a different effect of impairment of sperm production and maturation induced by inhalation of nanosized and microsized silicon dioxide, and nanosized silicon dioxide exerted more severe reaction.
authors.affiliation: Center for Disease Control and Prevention of Shandong Province, Jinan 250014, China.
authors.forename: Yi-Ou
authors.initials: YO
authors.lastname: Fan
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Zhang
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Zhang
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Yi-xin
authors.initials: YX
authors.lastname: Ma
authors.forename: Yi-he
authors.initials: YH
authors.lastname: Jin
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D019570:Inhalation Exposure; D008297:Male; D010316:Particle Size; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012822:Silicon Dioxide / Q000633:toxicity*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*; D013737:Testis / Q000473:pathology
chemical_list: D012822:Silicon Dioxide