Tsunoda Masashi, Aizawa Yoshiharu, Konno Nobuhiro, Kimura Kimiko, Sugita-Konishi Yoshiko
Department of Preventive Medicine and Public Health, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
Toxicol Ind Health. 2006 Feb;22(1):15-25. doi: 10.1191/0748233706th240oa.
Tributyltin (TBT) compounds have been used as anti-fouling agents and the central nervous system is one of its target organs. TBT-induced modulations of neurotransmitters in the brains of adult mice have been reported. However, little is known about the developmental neurotoxicity of TBT. In this study, we evaluated the effects of TBT on neurotransmitters and their metabolites in discrete brain regions of female ICR mice and their offspring. Pregnant ICR mice were exposed to TBT chloride at concentrations of 0, 15 or 50 ppm in water or 125 ppm in food. Male offspring were sacrificed at one, two and three weeks after birth. The concentrations of norepinephrine, dopamine (DA), dihydoxyphenylacetic acid, homovanillic acid (HVA), serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) were determined in different brain regions by HPLC. All offspring from the 125 ppm group died immediately after birth. A significant decrease in the body weight of the TBT-treated F1 groups compared to the control group was observed in the first week. Significant increases compared to the controls were observed for the DA concentration in the striatum of the 50 ppm F1 group, and for the HVA concentration in the cerebrum and the 5-HT concentration in the medulla oblongata of the 15 and 50 ppm F1 groups in the third week. At three weeks of age, the neurotransmitters and their metabolites may be useful indexes for developmental neurotoxicity. For the dams, a significant decrease in the 5-HT concentration was observed in the cerebellum, medulla, midbrain and striatum of the 125 ppm group compared to the control group. A significant decrease in the 5-HIAA concentration was also observed in the cerebellum, midbrain and striatum of the dams in the 125 ppm group compared to the control. TBT may induce a decrease in the synthesis of 5-HT in the dams. The discrepancy between dams and offspring may be due to several factors such as age, dose, route, sex and pregnancy.
三丁基锡(TBT)化合物曾被用作防污剂,中枢神经系统是其靶器官之一。已有报道称TBT会对成年小鼠大脑中的神经递质产生调节作用。然而,关于TBT的发育神经毒性却知之甚少。在本研究中,我们评估了TBT对雌性ICR小鼠及其后代不同脑区神经递质及其代谢物的影响。怀孕的ICR小鼠通过饮用浓度为0、15或50 ppm的含氯化TBT水或食用含125 ppm氯化TBT的食物来接触TBT。雄性后代在出生后1周、2周和3周时被处死。通过高效液相色谱法测定不同脑区中去甲肾上腺素、多巴胺(DA)、二羟苯乙酸、高香草酸(HVA)、5-羟色胺(5-HT)和5-羟吲哚乙酸(5-HIAA)的浓度。125 ppm组的所有后代在出生后立即死亡。在第一周,与对照组相比,经TBT处理的F1组体重显著下降。在第三周,50 ppm F1组纹状体中的DA浓度、15和50 ppm F1组大脑中的HVA浓度以及延髓中的5-HT浓度与对照组相比显著升高。在三周龄时,神经递质及其代谢物可能是发育神经毒性的有用指标。对于母鼠,与对照组相比,125 ppm组的小脑、延髓、中脑和纹状体中的5-HT浓度显著下降。与对照组相比,125 ppm组母鼠的小脑、中脑和纹状体中的5-HIAA浓度也显著下降。TBT可能会导致母鼠体内5-HT合成减少。母鼠和后代之间的差异可能是由年龄、剂量、途径、性别和怀孕等多种因素造成的。