title: Methyl tert-butyl ether (MTBE)-induced cytotoxicity and oxidative stress in isolated rat spermatogenic cells.
abstract: Methyl tert-butyl ether (MTBE) is a class of synthetic organic chemical. In the USA, MTBE pollution is regarded as a serious environmental problem. The objective of the present study was to investigate the cytotoxic effects and oxidative stress induced by MTBE in isolated rat spermatogenic cells. In cytotoxic experiments, spermatogenic cells isolated from the testes of adult Sprague-Dawley rats by a mechanical procedure without the use of trypsin were incubated with medium alone (control), 0.5, 5, 50 mm MTBE, respectively, for 6, 12 and 18 h. MTT assay, staining with fluorescein diacetate (FDA) and propidium iodide (PI) and flow cytometric analyses were used. In oxidative stress experiments, the spermatogenic cells were incubated with medium alone (control) and with 0.5, 50 microm, 5 mm MTBE. For 1, 2, 6, 12, 18 h incubation, ROS production was tested using a 2',7'-dichlorofluorescein diacetate (DCHF-DA) probe; for 1, 3, 6, 12, 18 h incubation, cytosolic superoxide dismutase (SOD) and extracellular SOD (SOD(EX)) activity was assessed; and for 18 h incubation, lipid peroxidation was assessed. The results showed that MTBE at high doses significantly decreased the spermatogenic cell viability and increased plasma membrane damage and the ratio of necrotic cells compared with the control. Assessment of the MTBE-induced oxidative stress revealed that MTBE increased the production of reactive oxygen species (ROS) and enhanced lipid peroxidation. In addition, although SOD(EX) activity increased at a high dose level, cytosolic SOD activity decreased. These results suggest that an increase of MTBE-induced ROS production and an enhancement of membrane lipid peroxidation may play an important role in its cytotoxicity in isolated rat spermatogenic cells.
authors.affiliation: Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, Nanjing, Jiangsu 210093, PR China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Li
authors.forename: Daqiang
authors.initials: D
authors.lastname: Yin
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Han
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D002469:Cell Separation / Q000379:methods; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008738:Methyl Ethers / Q000633:toxicity*; D009336:Necrosis; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D013090:Spermatocytes / Q000187:drug effects* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013737:Testis / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D008738:Methyl Ethers; D017382:Reactive Oxygen Species; C043243:methyl tert-butyl ether; D013482:Superoxide Dismutase