Experimental Study Of Lipid Peroxidation Injury In Rats Inhaled By Methyl Ethyl Ketone Peroxide

ObjectiveTo investigate pathological changes of major organs and the oxidative damage in the liver of rats after rats inhaled methyl ethyl ketone peroxide (MEKP) aerosol and provide clues for oxidative damage mechanism of methyl ethyl ketone peroxide and medical protection.MethodsSprague-Dawley rats were exposed to MEKP via whole body inhalation for6h/day,5d/week at targeted exposure levels of0mg/m3、50mg/m3、500mg/m3 and1000mg/m3for13weeks. One control group was exposed to filtered air, another control group was exposed to the solvent2,2,4-trimethyl-1,3-pentanediol diisobutyrate1. Organ coefficient and pathological damage of major organs observationHistopathological changes of the lung, kidney, spleen, testis of all rats were observed by conventional pathological techniques and organ weight changes.2. Determination of GSH, MDA content and SOD activity in rat liverSOD, MDA, GSH, and protein content were measured by TBA method and Coomassie brilliant blue staining method, GSH and MDA results were expressed as "pro" mg/g, SOD activity result was expressed as "U/mg pro.3.Rat liver enzyme CYP450and enzyme NADH content determinationAfter cutting samples, check the weight,add PBS (PH7.2-7.4), rapidly frozen with liquid nitrogen, maintain samples at2-8℃after melting,add PBS (PH7.4),6Homogenized by hand or Grinders, centrifugation20-min at the speed of2000-3000r.p.m. remove supernatant.Take a supernatant determine the sample OD value according to the ELISA kit analysis instructions.4. levels of AST, ALT, PLT in blood determinationAnesthesia rats with CO2, blood5mL from eye venous, add anticoagulant EDTA-2Na, determine levels of AST, ALT, PLT in blood in accordance with AST, ALT, PLT determination kit.5. Data processing:ANOVA significant difference test and the test data for multiple comparisons was conduct with SPASS17.0statistical analysis software, P＜0.05was considered statistically significant. Resultsl.Organ coefficient and pathological damage of major organsOrgan coefficient of kidney, thymus, testis weight of male rat in1000mg/m3group were significantly lower than each dose group, the control group and solvent control group, the liver and lung, and testis of some rats in the1000mg/m3group and500mg/m3group were significantly damaged, showing the trend of increasing severity with increasing dose. Bronchial damage was mainly ciliated epithelial shedding, degeneration, lymphocyte infiltration.2. GSH, MDA content,SOD activity in Rat liver.Compared with control rats and solvent control rats, the levels of GSH of male rats in500mg/m3group and1000mg/m3group, the levels of GSH of female rats in1000mg/m3group were significantly lower; compared with control rats and solvent control rats, the activity of SOD of male rats were significantly decreased in500mg/m3group and1000mg/m3group, the activity of SOD of female rats were significantly decreased in1000mg/m3group. The MDA levels of male rats were significantly higher in500mg/m3ansd1000mg/m3group, the MDA level of female rats was significantly higher in1000mg/m3group.3.OD values of NADH and cytochrome CYP450in rat liverCompared with control rats and solvent control rats, levels of NADH, CYP450were significantly reduced in500mg/m3and1000mg/m3group.4.Levels of AST、ALT、PLT in rat bloodCompared with control rats and solvent control rats and rats in50mg/m3group, levels of AST and ALT in blood of male rats were significantly increased in the500mg/m3and1000mg/m3group, the level of AST and ALT in blood of female rats in the1000mg/m3group was significantly increased. Levels of PLT in blood of rats in the1000mg/m3group were significantly lower than rats in other groups.Conclusion1.Trachea, lung, liver, spleen, testes of rats showed significant pathological damage inhalation of more than500mg/m3of MEKP aerosol, kidney, thymus, testis organ coefficient the male rat decreased significantly, testicular pathological damage is more serious.2.Rat inhalation over500mg/m3concentrations of MEKP aerosol, levels of oxidative stress in the liver have been seriously affected by lipid peroxidation, MDA content increased GSH content, SOD activity was significantly decreased.3.Rat inhalation over500mg/m3concentrations of MEKP aerosol, MEKP can be combined with CYP450, NADH, and inhibit its activity, elevated AST, ALT, PTL was reduced, the liver NADH P450activity decreased. MEKP aerosol can cause significant liver damage.