Age- and sex-dependent variation in the activity of antioxidant enzymes in the brown trout (Salmo trutta)
Oxidative stress is defined as the imbalance between pro-oxidant and antioxidant molecules in favor of the former and it represents one of the main driving forces of aging. To counteract the harmful effects of oxidative stress, organisms evolved a complex antioxidant system. According to the free radical theory of aging, while the production of reactive oxygen species (ROS) increases with age, the antioxidant defenses decline. Although this relationship has been investigated in diverse vertebrate taxa, the information in fish is scant and inconsistent, particularly for wild populations. Thus, the aim of the present study was the investigation of age- and sex-related changes of the antioxidant enzymes activity in free-living individuals of the brown trout (Salmo trutta). We measured the activity of the main enzymes involved in antioxidant protection, namely superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST), as well as lipid peroxidation, in the gills and the liver dissected from brown trout (1+- to 5+-year-old). A significant age-dependent variation in the activity of antioxidant enzymes was noted, with the exception of CAT. GPx activity followed a significant increasing trend with age in both the organs, while SOD decreased in the liver. Increased GST activity was found in the gills only. Lipid peroxidation levels significantly decreased with age in both the organs. SOD and CAT showed sex-dependent differences in the liver of brown trout, with males showing lower enzymatic activity than females. Our data contribute to improve the knowledge on the relationship between antioxidant enzyme activity, aging, and sex in fish.
KeywordsAntioxidant enzymes Lipid peroxidation Aging Brown trout Oxidative stress
We are very grateful to the Gran Paradiso National Park for the opportunity to perform this study. We would like to thank all the employers of the park surveillance involved during the sampling operations.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Almroth BC, Johansson A, Förlin L, Sturve J (2010) Early-age changes in oxidative stress in brown trout, Salmo trutta. Comp Biochemy Physiol B 155:442–448Google Scholar
- Halliwell B, Gutteridge JMC (1999) Free radicals in medicine and biology. Clarendon, OxfordGoogle Scholar
- Sanz A, Hidalgo MC, Morales AE, Cillero C, Domezain A, Domezain J, Garcia-Gallego M (2001) Evolution of antioxidant defenses and lipid peroxidation with age in the sturgeon Acipenser naccarii. In: Proceedings of the 4th International Symposium on Sturgeon, July 8–13, Oshkosh, WI, pp. 89Google Scholar
- Salo DC, Lin SW, Pacifici RE, Davies KJA (1988) Superoxide dismutase is preferentially degraded by a proteolytic system from red blood cells following oxidative modification by hydrogen peroxide. Free Rad Biol Med 5:335–339Google Scholar