Abstract: ObjectiveTo explore the effect of methyl tertiary-butyl ether(MTBE)on ATPase and ultrastructure of brain tissue of fetal mice during gestation.MethodsForty healthy and pregnant KM mice were distributed in five groups randomly.The MTBE exposure doses were 800,400,100,25 and 0 mg/kg·bw by gavage from the 0 day to the end of gestation,once per day.The levels of ATPase activity were checked and the ultrastructure in the brain tissue of the fetal mice was observed.ResultsCompared with the control,the level of ATPase activity in brain tissue of fetal mice was increased at the exposure doses of 25 and 100 mg/kg·bw(P>0.05).The levels of Na⁺,K⁺-ATPase,Ca²⁺-ATPase,Mg²⁺-ATPase activity in brain tissue of fetal mice were decreased when the exposure dose was 400 mg/kg·bw(Na⁺,K⁺-ATPase=5.28±0.24 μmol pi/mg·prot/h,Ca²⁺-ATPase=5.92±0.50μmol pi/mg·prot/h,Mg²⁺-ATPase=2.39±0.21μmol pi/mg·prot/hr, P<0.05).The levels of Na⁺,K⁺-ATPase,Ca²⁺-ATPase dereased significantly when the exposure dose increased to 800 mg/kg·bw(Na⁺,K⁺-ATPase=5.01±0.57μmol pi/mg·prot/h,Ca²⁺-ATPase=5.60±0.37μmol pi/mg·prot/hr, P<0.01).The ultrastructural changes of brain tissue of fetal mice with pregnant mice exposed to MTBE during gestation were edema and degeneration of the nerve cell and neuroglia cell and the damages of mitochondria and cell membrane.ConclusionMTBE could induce subcellular structure changes of brain tissue of fetal mice and decreased the activity of ATPase during gestation.