Aydin Yasemin, Erkan Melike
Department of Biology, Faculty of Science, Istanbul University, Istanbul, Turkey.
Toxicol Ind Health. 2017 Aug;33(8):636-645. doi: 10.1177/0748233717699783. Epub 2017 May 15.
Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental contaminants that disrupt endocrine function in biological systems, especially in the male reproductive system. Previous studies on the reproductive toxicity of PCBs have focused on the impairment of spermatogenesis, disruption of steroidogenesis, decreased sperm number, and infertility. Aroclor 1242 is a commercial mixture with an average of 42% chlorine by weight. The purpose of the present study was to elucidate the hazardous effects of Aroclor 1242 on Leydig cells through an evaluation of cell viability, lipid peroxidation, hydroxyl radicals, HO production, antioxidant enzymes, and steroidogenic enzymes. Leydig cells were exposed to Aroclor 1242 for 24 h under basal and luteinizing hormone-stimulated conditions at different concentrations (ranging from 10 M to 10 M). After incubation, Leydig cells were measured for cell viability, lipid peroxidation, reactive oxygen species (hydroxyl radical and HO), antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase), and steroidogenic enzymes (3β-hydroxysteroid dehydrogenase [HSD] and 17β-HSD). The results showed that cell viability was reduced only at Aroclor 1242 concentrations of 10 M and 10 M, whereas lipid peroxidation and reactive oxygen species increased relative to the concentration. Furthermore, antioxidant systems and steroidogenesis were interrupted to varying degrees, relative to the concentration. These findings suggest that exposure to Aroclor 1242 at high concentrations may result in detrimental effects to Leydig cell homeostasis. In addition, Aroclor 1242 may impair steroidogenesis, especially testosterone biosynthesis, by inhibiting two important steroidogenic enzymes.
多氯联苯（PCBs）是普遍存在且持久的环境污染物，会扰乱生物系统中的内分泌功能，尤其是雄性生殖系统。先前关于多氯联苯生殖毒性的研究主要集中在精子发生受损、类固醇生成紊乱、精子数量减少和不育等方面。Aroclor 1242是一种商业混合物，平均含氯量为42%（按重量计）。本研究的目的是通过评估细胞活力、脂质过氧化、羟基自由基、HO产生、抗氧化酶和类固醇生成酶，阐明Aroclor 1242对睾丸间质细胞的有害影响。在基础和促黄体生成素刺激条件下，将睾丸间质细胞暴露于不同浓度（范围从10⁻⁶M到10⁻⁴M）的Aroclor 1242中24小时。孵育后，检测睾丸间质细胞的细胞活力、脂质过氧化、活性氧（羟基自由基和HO）、抗氧化酶（过氧化氢酶、超氧化物歧化酶、谷胱甘肽过氧化物酶和谷胱甘肽-S-转移酶）以及类固醇生成酶（3β-羟基类固醇脱氢酶 [HSD] 和17β-HSD）。结果表明，仅在Aroclor 1242浓度为10⁻⁶M和10⁻⁴M时细胞活力降低，而脂质过氧化和活性氧随浓度增加。此外，抗氧化系统和类固醇生成相对于浓度受到不同程度的干扰。这些发现表明，高浓度暴露于Aroclor 1242可能对睾丸间质细胞的内环境稳定产生有害影响。此外，Aroclor 1242可能通过抑制两种重要的类固醇生成酶来损害类固醇生成，尤其是睾酮的生物合成。
