College of Life Sciences, Qufu Normal University, Qufu Shandong 273165, China.
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Zool Res. 2019 Jul 18;40(4):305-316. doi: 10.24272/j.issn.2095-8137.2019.045. Epub 2019 Apr 10.
Ambient temperature is an important factor influencing many physiological processes, including antioxidant defense and immunity. In the present study, we tested the hypothesis that antioxidant defense and immunity are suppressed by high and low temperature treatment in Brandt's voles (). Thirty male voles were randomly assigned into different temperature groups (4, 23, and 32 °C, =10 for each group), with the treatment course lasting for 27 d. Results showed that low temperature increased gross energy intake (GEI) and liver, heart, and kidney mass, but decreased body fat mass and dry carcass mass. With the decline in temperature, hydrogen peroxide (HO) concentration, which is indicative of reactive oxygen species (ROS) levels, increased in the liver, decreased in the heart, and was unchanged in the kidney, testis, and small intestine. Lipid peroxidation indicated by malonaldehyde (MDA) content in the liver, heart, kidney, testis, and small intestine did not differ among groups, implying that high and low temperature did not cause oxidative damage. Similarly, superoxide dismutase (SOD) and catalase (CAT) activities and total antioxidant capacity (T-AOC) in the five tissues did not respond to low or high temperature, except for elevation of CAT activity in the testis upon cold exposure. Bacteria killing capacity, which is indicative of innate immunity, was nearly suppressed in the 4 °C group in contrast to the 23 °C group, whereas spleen mass and white blood cells were unaffected by temperature treatment. The levels of testosterone, but not corticosterone, were influenced by temperature treatment, though neither were correlated with innate immunity, HO and MDA levels, or SOD, CAT, and T-AOC activity in any detected tissues. Overall, these results showed that temperature had different influences on oxidative stress, antioxidant enzymes, and immunity, which depended on the tissues and parameters tested. Up-regulation or maintenance of antioxidant defense might be an important mechanism for voles to survive highly variable environmental temperatures.
环境温度是影响许多生理过程的重要因素，包括抗氧化防御和免疫。本研究旨在检验以下假设：高温和低温处理会抑制布氏田鼠的抗氧化防御和免疫。30 只雄性田鼠被随机分配到不同的温度组（4、23 和 32°C，每组 10 只），处理时间为 27 天。结果表明，低温组增加了总能量摄入量（GEI）和肝脏、心脏和肾脏的质量，但降低了体脂质量和干体质量。随着温度的降低，肝脏中指示活性氧（ROS）水平的过氧化氢（HO）浓度增加，心脏中减少，肾脏、睾丸和小肠中不变。肝脏、心脏、肾脏、睾丸和小肠中丙二醛（MDA）含量表示的脂质过氧化在各组之间没有差异，表明高温和低温没有造成氧化损伤。同样，除了冷暴露导致睾丸中 CAT 活性升高外，五种组织中的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性和总抗氧化能力（T-AOC）均未对低温或高温作出响应。与 23°C 组相比，4°C 组的细菌杀伤能力几乎被抑制，而脾脏质量和白细胞不受温度处理的影响。尽管皮质酮与先天免疫、HO 和 MDA 水平或任何检测组织中的 SOD、CAT 和 T-AOC 活性均无相关性，但温度处理影响了睾酮水平，而非皮质酮水平。总之，这些结果表明，温度对氧化应激、抗氧化酶和免疫有不同的影响，这取决于所测试的组织和参数。上调或维持抗氧化防御可能是田鼠在高度变化的环境温度下生存的重要机制。
