Antioxidant Defense System of Tadpoles (Eupemphix nattereri) Exposed to Changes in Temperature and pH

Autor(es)

Freitas, Juliane S. ^[1] ; Almeida, Eduardo A. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Dept Chem & Environm Sci, Grad Program Anim Biol, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Estadual Paulista, Dept Chem & Environm Sci, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ZOOLOGICAL SCIENCE; v. 33, n. 2, p. 186-194, APR 2016.
• Citações Web of Science: 7

Resumo

Amphibians are highly susceptible to environmental changes, mainly at the larval stage during which they are restricted to small and ephemeral aquatic habitats, which are subject to large fluctuations of abiotic parameters, such as temperature and pH. Consequently, tadpoles experience changes in biochemical, physiological, and molecular processes related to the maintenance of homeostasis, which may lead them to an oxidative stress state. In the present study, we investigated the effects of stress caused by changes in temperature and pH on the antioxidant enzymes catalase (CAT), glucose-6-phosphate dehydrogenase (G6PDH), glutathione reductase (GR) and glutathione-S-transferase (GST) in tadpoles of Eupemphix nattereri. The results show that changes in temperature and pH conditions induce an antioxidant response in tadpoles. GST and GR showed temperature-dependent activities; GST activity was higher in tadpoles exposed to 28 degrees C, whereas GR exhibited increased activity in response to 28 degrees C and 36 degrees C. At 32 degrees C, both GST and GR had the lowest activity. CAT was induced by treatments with acidic (pH 5.0) and alkaline (pH 8.5) pH. Tadpoles exposed to acidic pH also had increased GR activity. The G6PDH was not changed in either experiment. Our data demonstrate that E. nattereri possesses an efficient antioxidant defense system for coping with the damaging effects of heat and acidity/alkalinity conditions in water. The alterations in antioxidant enzymes are probably a result of immediate physiological adaptation of individuals in response to increased production of ROS under environmental stress conditions. (AU)

• Processo FAPESP: 13/16948-3 - Influência da temperatura na toxicidade dos herbicidas Boral 500SC® e GAMIT em larvas de anuros Eupemphix nattereri (Leptodactylidae) e Rhinella schneideri (Bufonidae)
• Beneficiário: Juliane Silberschmidt Freitas
• Modalidade de apoio: Bolsas no Brasil - Doutorado