Effect of nanoparticle-rich diesel exhaust on testicular and hippocampus steroidogenesis in male rats
Effect of nanoparticle-rich diesel exhaust on testicular and hippocampus steroidogenesis in male rats
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DOI：
10.3109/08958378.2012.688225
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发表时间：
2012-07-01
影响因子：
2.1
通讯作者：
Nakajima, Tamie
中科院分区：
文献类型：
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作者：
Yamagishi, Nozomi;Ito, Yuki;Nakajima, Tamie
背景：富含纳米颗粒的柴油机尾气（NR-DE）对睾丸类固醇生成有潜在的不良影响。目的：研究NR-DE对成年雄性大鼠海马甾体激素合成的影响，并与对睾丸的影响进行比较。F344雄性大鼠（8周龄）随机分为4组（每组n = 8或9），并暴露于质量浓度为4.6 +/- 3.2 μ g/m3的清洁空气中，NR-DE为38 +/- 3 μ g/m3（几乎相当于日本环境标准（低NR-DE）），NR-DE为149 +/- 8 μ g/m（3）（高NR-DE），或过滤后的柴油废气，3.1 +/- 1.9 μ g/m3（F-DE），5小时/天，5天/周，持续1，2或3个月。结果：高NR-DE暴露1个月，低NR-DE暴露2个月，大鼠血浆和睾丸睾酮水平较清洁空气暴露显著升高或有升高趋势，这可能与大鼠睾丸类固醇生成急性调节蛋白mRNA及其蛋白表达增加有关。在海马中，高NR-DE暴露1个月的雄烯二酮水平显着增加相比，清洁空气暴露，而没有显着差异，观察在新鲜空气暴露之间的类固醇生成与任何暴露于NR-DE或F-DE。结论：NR-DE可能会影响睾丸中的类固醇生成酶，但不影响海马中的类固醇生成酶。
Background: Nanoparticle-rich diesel exhaust (NR-DE) has potentially adverse effects on testicular steroidogenesis. However, it is unclear whether NR-DE influences steroidogenic systems in the brain.Objective: To investigate the effect of NR-DE on hippocampal steroidogenesis of adult male rats in comparison with its effect on the testis.Methods: F344 male rats (8-week-old) were randomly divided into four groups (n = 8 or 9 per group) and exposed to clean air with 4.6 +/- 3.2 mu g/m(3) in mass concentration, NR-DE with 38 +/- 3 mu g/m(3) (a level nearly equivalent to the environmental standard in Japan (low NR-DE)), NR-DE with 149 +/- 8 mu g/m(3) (high NR-DE), or filtered diesel exhaust with 3.1 +/- 1.9 mu g/m(3) (F-DE), for 5 hours/day, 5 days/week, for 1, 2 or 3 months. F-DE was prepared by removing only particulate matters from high NR-DE with an HEPA filter.Results: Exposures to the high NR-DE for 1 month, and low NR-DE for 2 months, significantly increased or tended to increase plasma and testicular testosterone levels compared to clean air exposure, which might have resulted from the increased expression of mRNA of steroidogenic acute regulatory protein and its protein in the testes of rats. In the hippocampus, high NR-DE exposure for 1 month significantly increased the androstendione level compared to the clean air exposure, while no significant difference was observed in the steroidogenesis between fresh air exposure and any exposure to NR-DE or F-DE.Conclusion: NR-DE may influence steroidogenic enzymes in the testis, but not those in the hippocampus.