Effects of acclimation and incubation temperature on the glutathione antioxidant system in killifish and RTH-149 cells

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Vol. 146; no. 3; pp. 317 - 326
• Main Authors: Leggatt, R.A., Brauner, C.J., Schulte, P.M., Iwama, G.K.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2007
• Subjects: Acclimatization - physiology; Animals; Antioxidants - physiology; Brackish; Cell Line, Tumor; Fish; Freshwater; Fundulidae - physiology; Glutathione; Glutathione - physiology; Glutathione Disulfide - metabolism; Glutathione peroxidase; Glutathione Peroxidase - metabolism; Glutathione reductase; Glutathione Reductase - metabolism; Killifish; L-Lactate Dehydrogenase - metabolism; Mammals; Marine; Oncorhynchus mykiss; RTH-149 cells; Temperature; Glutathione peroxidase; Temperature; RTH-149 cells; Glutathione reductase; Killifish; Fish; Mammals; Glutathione
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/j.cbpa.2006.10.033

Glutathione (GSH) is an important antioxidant that is involved in a multitude of cellular processes. However, in fish, GSH levels, turnover, and activity of associated enzymes are low when compared to those of mammals. To determine whether temperature influences the GSH antioxidant system in fish, and can explain the differences in GSH between fish and mammals, we examined the effects of acclimation temperature on total GSH (tGSH) levels and apparent half-life (as an estimate of turnover) in a rainbow trout hepatoma cell line (RTH-149), and GSH levels, and glutathione peroxidase (GPx) and reductase (GR) activity in the eurythermal killifish. Increasing incubation temperature decreased half-life and transiently increased levels of tGSH in RTH-149 cells. In killifish, increased acclimation temperature increased tGSH levels in the liver, brain and muscle, and increased hepatic GPx and GR activities. When the relationships between temperature and GSH half-life, levels and enzyme activity were extrapolated to 37 °C, temperature could only partially accounted for differences in the GSH antioxidant system in fish compared to mammals. The differences in the GSH antioxidant system between fish and mammals may not be solely due to temperature effects, but also to the increased metabolic cost of endothermy in mammals.