Antioxidant responses in hibernating Chinese soft-shelled turtle Pelodiscus sinensis hatchlings.
The antioxidant defense system protects turtles from oxidative stress during hibernation. The present study examined changes of the antioxidant enzymes both on mRNA level and enzyme activity level during hibernation of Chinese soft-shelled turtle Pelodiscus sinensis hatchlings. The upstream regulator NF-E2 related factor 2 (Nrf2) mRNA was also measured. Samples were taken at pre-hibernation (17.0°C, Mud temperature (MT)), hibernation (5.8°C, MT) and arousal (20.1°C, MT). Nrf2 exhibited a tissue-specific pattern of expression with a decrease in the brain, slight increase in the liver and heart during hibernation, and significant increase during arousal in all the three tissues. Superoxide dismutase (SOD) mRNA, catalase (CAT) mRNA, and glutathione peroxidase 3 (GPx3) mRNA exhibited a similar pattern as Nrf2 in the brain and liver during the entire hibernation period. Hepatic GPx4 mRNA level increased during hibernation and decreased during arousal, whereas it did not change in the heart. Cerebral SOD and CAT activities kept stable during the experimental period, but GPx activity decreased significantly during hibernation and arousal. Hepatic GPx enzyme activity did not change, whereas those of SOD and CAT exhibited a notable decrease during arousal. Malondialdehyde concentration did not increase during the hibernation process, indicating an effective protection of the antioxidant defense system.
Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China.
Wen-Yi
WY
Zhang
Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China. Electronic address: cjniu@bnu.edu.cn.
Cui-Juan
CJ
Niu
Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China.
Bo-Jian
BJ
Chen
Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China.
Lin
L
Yuan
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000201:enzymology / Q000378:metabolism; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D006605:Hibernation; D008315:Malondialdehyde / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014426:Turtles / Q000502:physiology*
D000975:Antioxidants; D051267:NF-E2-Related Factor 2; D008315:Malondialdehyde; D002374:Catalase; D013482:Superoxide Dismutase
Antioxidant enzymes; Hibernation; Soft-shelled turtle hatchlings; Tissue specific changing pattern; mRNA level