title: Effect of oral methyl-t-butyl ether (MTBE) on the male mouse reproductive tract and oxidative stress in liver.
abstract: MTBE is found in water supplies used for drinking and other purposes. These experiments follow up on earlier reports of reproductive tract alterations in male mice exposed orally to MTBE and explored oxidative stress as a mode of action. CD-1 mice were gavaged with 400-2000 mg/kg MTBE on days 1, 3, and 5, injected i.p. with hCG (2.5 IU/g) on day 6, and necropsied on day 7. No effect was seen in testis histology or testosterone levels. Using a similar dosing protocol, others had initially reported disruption of seminiferous tubules in MTBE-gavaged mice, although later conclusions published were consistent with our findings. Another group had also reported testicular and other reproductive system abnormalities in male BALB/c mice exposed for 28 days to 80-8000 microg/ml MTBE in drinking water. We gave these MTBE concentrations to adult mice for 28 days and juvenile mice for 51 days through PND 77. Evidence of oxidative stress was examined in liver homogenates from the juvenile study using MDA, TEAC and 8OH2hG as endpoints. MTBE exposures at the levels examined indicated no significant changes in the male mouse reproductive tract and no signs of hepatic oxidative stress. This appears to be the first oral MTBE exposure of juvenile animals, and also the first to examine potential for MTBE to cause oxidative stress in vivo using a typical route of human exposure.
authors.affiliation: Graduate School of Public Health, San Diego State University, San Diego, CA 92182, United States. adepeyst@mail.sdsu.edu
authors.forename: Ann
authors.initials: A
authors.lastname: de Peyster
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Rodriguez
authors.forename: Rika
authors.initials: R
authors.lastname: Shuto
authors.forename: Beck
authors.initials: B
authors.lastname: Goldberg
authors.forename: Frank
authors.initials: F
authors.lastname: Gonzales
authors.forename: Xinzhu
authors.initials: X
authors.lastname: Pu
authors.forename: James E
authors.initials: JE
authors.lastname: Klaunig
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D005837:Genitalia, Male / Q000187:drug effects*; D015227:Lipid Peroxidation; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008738:Methyl Ethers / Q000633:toxicity*; D051379:Mice; D008807:Mice, Inbred BALB C; D009929:Organ Size / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D008738:Methyl Ethers; C043243:methyl tert-butyl ether