Antioxidant enzymatic defenses and oxidative damage in Dentex dentex fed on different dietary macronutrient levels.
A wide range of antioxidant mechanisms are present in fish maintaining an adequate "oxidative balance". When this balance tilts in favor of the oxidant agents "oxidative stress" arises with detrimental effects in molecules of great biological importance. Little has been reported about the influence of different dietary energy sources on antioxidant defenses in fish. The influence of different dietary macronutrient combinations on the key antioxidant enzyme activity, the oxidative damage to lipids and proteins and the possible modifications in the SOD isoenzymatic pattern were evaluated in liver, white muscle, heart and erythrocytes of common dentex (Dentex dentex). Four experimental diets with different protein:lipid:carbohydrate ratios (43/16/28; 43/24/4; 38/19/28 and 38/24/13) were formulated. In general, neither different dietary macronutrient levels nor the interaction among them induces substantial modifications in enzymatic antioxidant defense mechanisms. Two constitutive SOD isoforms, CuZn-SOD I and Mn-SOD, were detected in the tissues analyzed in all experimental groups, independently of diet formulation, but, a third SOD isoenzyme, CuZn-SOD II seems to be induced in white muscle by higher dietary protein levels. Densitometric analyses of western blotting membranes revealed higher CuZn-SOD expression in the heart of dentex fed on lower dietary protein levels, although these differences did not correlate with the SOD activity. Finally, a direct relation exists between the lipid or protein intake level and occurrence of oxidative damage in different tissue components.
Pérez-Jiménez
Amalia
A
Departamento de Biología Animal, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain. calaya@ugr.es
Hidalgo
M Carmen
MC
Morales
Amalia E
AE
Arizcun
Marta
M
Abellán
Emilia
E
Cardenete
Gabriel
G
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000378:metabolism / Q000494:pharmacology*; D004041:Dietary Fats / Q000378:metabolism / Q000494:pharmacology*; D004044:Dietary Proteins / Q000378:metabolism / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D004912:Erythrocytes / Q000201:enzymology; D005526:Food, Formulated; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D050356:Lipid Metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000201:enzymology; D018482:Muscle, Skeletal / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D018384:Oxidative Stress / Q000187:drug effects*; D010473:Perciformes / Q000378:metabolism*; D011897:Random Allocation; D012015:Reference Standards; D012995:Solubility; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D000975:Antioxidants; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D007527:Isoenzymes; D017392:Thiobarbituric Acid Reactive Substances; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase