The effect of dietary intake of vitamins C and E on the stress response of gilthead seabream (Sparus aurata L.).
High dietary doses of the antioxidant vitamins C and E were administered to gilthead seabream (Sparus aurata L.) in an attempt to reduce the stress response in specimens exposed to a multiple stress situation. Fish were fed four different diets for 6 weeks: a commercial feed containing 0.1g vitamin C and 0.1g vitamin E kg(-1) acted as control diet, while experimental diets consisted of the same feed supplemented with 3g vitamin C kg(-1), 1.2g vitamin E kg(-1) or both 3g vitamin C and 1.2g vitamin E kg(-1). After 2, 4 and 6 weeks fish were exposed to stressors typical of aquacultural practices, and serum cortisol levels, complement activity (measured by the alternative pathway), blood glucose level and respiratory burst activity of head-kidney leucocytes were evaluated. The results showed that all stress-induced increases in blood glucose concentration were lower in fish fed the vitamin C and/or E-supplemented diet than in fish fed the control diet after 2 weeks of treatment, although no other differences were found at the rest of the times. Cortisol levels increased in stressed fish and did not suffer depletion as a consequence of administering vitamins C and/or E as a supplement. The natural haemolytic complement activity was not affected by the stressors but enhanced in specimens fed vitamin-supplemented diets at week 6. The respiratory burst activity was depressed by the stressors in fish fed the control diet, although only after 6 weeks of treatment were the differences statistically significant. These results suggest that vitamins C and E are involved in the hypothalamic-sympathetic-chromaffin cell axis and also interfere in tertiary stress responses such as immunodepression, where they protect the leucocyte functions.
Ortuño
J
J
Department of Cell Biology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain.
Esteban
M A
MA
Meseguer
J
J
D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage* / Q000494:pharmacology; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000494:pharmacology; D001786:Blood Glucose / Q000187:drug effects; D015941:Complement Hemolytic Activity Assay; D003165:Complement System Proteins / Q000187:drug effects / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D006854:Hydrocortisone / Q000097:blood; D011897:Random Allocation; D016897:Respiratory Burst / Q000187:drug effects; D021541:Sea Bream / Q000276:immunology*; D013312:Stress, Physiological / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D014810:Vitamin E / Q000008:administration & dosage* / Q000494:pharmacology
D000975:Antioxidants; D001786:Blood Glucose; D014810:Vitamin E; D003165:Complement System Proteins; D001205:Ascorbic Acid; D006854:Hydrocortisone