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Phthalate esters (PAEs) are a class of synthetic organic compounds, production capacity, wide application. Since PAEs in the relevant product was free state, so you can transfer into the environment and thus the atmosphere, soil, water bodies caused serious pollution, and through food, breathing, drinking water and skin contact, and other ways to enter the human body, causing harm. Dibutyl phthalate (DBP) is the most common form of PAEs, because of its production capacity, application of a wide range of diverse and complex toxicological effects people's attention. Studies have shown that, DBP low acute toxicity and high doses (eg 500 mg / kg / d) Repeat exposure mainly for animal reproductive system has some damage. Our previous studies have shown that low doses of DBP metabolites in vitro effects of steroid hormone synthesis. This study was designed to explore whether DBP at lower doses affect reproductive function in male rats. Part I: low dose of dibutyl phthalate (DBP) for the adolescent male SD rat testis function of the purpose of adolescent male SD rats as animal model to study the impact of DBP their testicular function. Methods DBP on 5-week-old male SD rats were gavage for 30 days, exposure dose, including: 0.1,1.0,10,100,500 mg / kg / d, exposed to the volume determined in accordance with the standard 0.5 mL/100g the control group, according to the same criteria given only solvent ─ corn oil. Assay indicators include: testis, epididymis weight, testicular histopathology, serum reproductive hormones (T, E2, LH, FSH) levels, changes in gene expression (StAR, SR, PCNA, etc.). Results 500 mg / kg / d for DBP inhibits testis, epididymis development, damage the seminiferous tubules and spermatogenesis, breaking the serum T, E2, LH and FSH balance between. 500 mg / kg / d DBP exposed group, StAR, PCNA mRNA levels are significantly decreased, while the expression of other genes unaffected. Low-dose (0.1,1.0,10 mg / kg / d) DBP elevated serum hormone levels: 0.1 mg / kg / d group E2 levels were significantly increased; 0.1 and 10 mg / kg / d group, LH levels were significantly elevated; 1.0 and 10 mg / kg / d dose group significantly higher FSH. Conclusion 500 mg / kg / d of DBP on adolescent SD rats produced a significant anti-androgen effect, affecting the rat testis and epididymis of normal development, damage the testes spermatogenesis, destroying a serum reproductive hormone balance, but lower doses of DBP did not produce a corresponding change; low dose (0.1,1.0,10 mg / kg / d) DBP on serum hormone levels has a stimulating effect, but the exact mechanism is unclear, pending further study. Part II: low doses of dibutyl phthalate (DBP) adolescent male SD rats induced testicular changes in protein expression profiling studies Objective Proteomics study low dose DBP (0.1,1.0,10 mg / kg / d) of adolescent males SD rat testis protein expression profile in order to discover the role of DBP in rat testis target protein, while DBP affect adolescent rats explore the molecular mechanisms of testicular function. Methods exposed for 30 days, from the control group and each exposure group were randomly selected three two-dimensional electrophoresis of testicular extract protein; polyacrylamide gel electrophoresis using ImageMaster 2D Platinum software analysis, for protein expression profiles compared; MALDI-TOF/TOFTM identification of differentially expressed protein; DAVID 2.0 analysis tools to analyze the structure of proteins in subcellular localization; PathwayStudio analyze proteins involved in the regulation of pathways; Finally, Western Blot verification 2-DE protein (HnRNPA2/B1, Vimentin, SOD1) expression trends, the immune These proteins were detected in normal testis intracellular localization. Experimental results were identified 45 differentially expressed proteins. Most of differentially expressed proteins located in the cytoplasm, nucleus, cytoskeleton, mitochondria; protein involved in biological processes including: cell differentiation, cell proliferation, apoptosis, mitosis, meiosis, oxidative stress, and so on. HnRNPA2/B1, Vimentin, SOD1 in Western Blot and 2-DE expression is consistent with the trend, they were located in the rat testis germ cells, Sertoli cells, Leydig cells. Conclusions No significant morphological changes in the case of low dose caused a testicular DBP protein profiles change. Differentially expressed proteins are widely distributed in cells involved in diverse biological processes, suggesting that the effect of DBP on the testis is complex and multifaceted. In addition, Sertoli cell skeleton, spermatogenesis, testicular oxidative stress is the impact of DBP on three important aspects of these in-depth research will help us to reveal the mechanism of reproductive toxicity of DBP.
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