Toxicity of methyl tertiary-butyl ether (MTBE) following exposure of Wistar Rats for 13weeks or one year via drinking water

摘要

Thirteen-week and one-year toxicity studies of methyl tertiary-butyl ether (MTBE) administered in drinking water to Wistar rats were conducted. Male and female rats were exposed to MTBE in drinking water at 0.5, 3, 7.5 and 15mg ml -1 for 13weeks and at 0.5, 3 and 7.5 (males) or 0.5, 3 and 15mg ml -1 (females) for 1year. Body weights were reduced only in males following 13weeks of exposure. Reduced water consumption and urine output were observed in males and females exposed to MTBE. Kidney cell replication and α 2u-globulin levels in males were increased at 1 and 4weeks of MTBE exposure and tubular cell regeneration was increased in male kidneys exposed to MTBE concentrations of 7.5mg ml -1 or greater for 13weeks. Wet weights of male kidneys were increased following 13weeks, 6months and 1year of exposure to MTBE concentrations of 7.5mg ml -1 or greater. Kidney wet weights were increased in females at MTBE concentrations of 15mg ml -1 for 13weeks. Tertiary-butyl alcohol blood levels increased linearly with dose in males and females following 1year of exposure. Chronic progressive nephropathy (CPN), of minimal to mild severity, increased in males, but not females, with 1year of MTBE exposure. In summary, exposure of Wistar rats to MTBE in the drinking water resulted in minimal exposure-related effects including limited renal changes in male rats suggestive of α 2u-globulin nephropathy following 13weeks of exposure and an exacerbation of CPN in males at the end of 1year of exposure.