Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
J Toxicol Environ Health A. 2012;75(16-17):971-80. doi: 10.1080/15287394.2012.695985.
Environmental tobacco smoke (ETS) leads to the death of 600,000 nonsmokers annually and is associated with disturbances in antioxidant enzyme capacity in the adult rodent brain. However, little is known regarding the influence of ETS on brain development. The aim of this study was to determine levels of malonaldehyde (MDA) and 3-nitrotyrosine (3-NT), as well as enzymatic antioxidant activities of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and superoxide dismutase (SOD), in distinct brain structures. BALB/c mice were exposed to ETS twice daily for 1 h from postnatal day 5 through postnatal day 18. Acute exposure was performed for 1 h on postnatal day 18. Mice were euthanized either immediately (0) or 3 h after the last exposure. Immediately after an acute exposure there were higher GR and GST activities and MDA levels in the hippocampus, higher GPx and SOD activities in the prefrontal cortex, and higher GST activity and MDA levels in the striatum and cerebellum. Three hours later there was an increase in SOD activity and MDA levels in the hippocampus and a decrease in the activity of all enzymes in the prefrontal cortex. Immediately after final repeated exposure there were elevated levels of GST and GR activity and decreased GPx activity in the hippocampus. Moreover, a rise was found in GPx and GST activities in the prefrontal cortex and increased GST and GPx activity in the striatum and cerebellum, respectively. After 3 h the prefrontal cortex showed elevated GR and GST activities, and the striatum displayed enhanced GST activity. Data showed that enzymatic antioxidant system in the central nervous system responds to ETS differently in different regions of the brain and that a form of adaptation occurs after several days of exposure.
环境烟草烟雾（ETS）每年导致 60 万不吸烟者死亡，并且与成年啮齿动物大脑中的抗氧化酶能力紊乱有关。然而，对于 ETS 对大脑发育的影响知之甚少。本研究旨在确定丙二醛（MDA）和 3-硝基酪氨酸（3-NT）的水平，以及谷胱甘肽过氧化物酶（GPx）、谷胱甘肽还原酶（GR）、谷胱甘肽 S-转移酶（GST）和超氧化物歧化酶（SOD）在不同脑结构中的酶抗氧化活性。BALB/c 小鼠从出生后第 5 天到第 18 天每天两次接受 ETS 暴露 1 小时。出生后第 18 天进行急性暴露 1 小时。在最后一次暴露后立即（0）或 3 小时后处死小鼠。急性暴露后，海马中 GR 和 GST 活性以及 MDA 水平升高，前额叶皮质中 GPx 和 SOD 活性升高，纹状体和小脑中 GST 活性和 MDA 水平升高。3 小时后，海马中 SOD 活性和 MDA 水平升高，前额叶皮质中所有酶的活性降低。最后一次重复暴露后，海马中 GST 和 GR 活性升高，GPx 活性降低。此外，前额叶皮质中 GPx 和 GST 活性升高，纹状体和小脑中 GST 和 GPx 活性分别升高。3 小时后，前额叶皮质中 GR 和 GST 活性升高，纹状体中 GST 活性增强。研究结果表明，中枢神经系统的酶抗氧化系统在大脑的不同区域对 ETS 的反应不同，并且在暴露几天后会发生一种适应形式。
