Synopsis
In a 3 × 2 factorial experiment examining the effects of combinations of ambient temperature (18°, 15°, 9° C) and dietary protein content (35% and 45%) on thyroid activity inSalmo gairdneri, although there was an apparent increase in activity of the thyroid in cold-adapted trout, assessed by histological appearance of the gland, there were no significant changes in serum thyroid hormone titers. In a second experiment examining the effects of combinations of ambient temperature (15°, 12.5°, 10°C) with dietary lipid content (6% and 16%) there was a similar apparent increase in thyroid activity in cold-adapted fish which was accompanied, in fish fed the higher lipid diet, with an increase in serum thyroxine (T4) and triiodothyronine (T3) levels.
Trout fed an ascorbic acid-free diet (experiment 3) had lower serum T3 levels than in those given an ascorbic acid supplemented diet (1280 mg·kg-1).
In experiments 2 and 3 serum thyroid hormone concentrations were approximately inversely proportional to ambient temperature and concomitant weight gain, but no such correlation was evident in experiment 1 suggesting that the changes in hormone levels in experiments 2 and 3 were not ipso facto related to differences in either ambient temperature or weight gain but rather to the specific metabolic changes imposed by the dietary lipids or ascorbic acid deficiency.
References cited
Alexander, N. M. & M. Nishimoto. 1978. Negligible effects of nonesterified fatty acids on serum thyroxine analysis by competitive protein-binding radioassay on Sephadex and by radio immunoassay. Clin. Chem. 24: 751–755.
Barnet, B. J., C. Y. Cho & S. J. Slinger. 1979. The essentiality of cholecalciferol in the diets of rainbow trout (Salmo gairdneri). Comp. Biochem. Physiol. in press.
Bastomsky, C. H., M. P. McQuaid & N. E. Greenidge. 1977. Minimal effects of free fatty acids on the competitive protein-binding assay of serum thyroxine on reusable Sephadex columns. Clin. Chem. Acta 75: 475–479.
Cho, C. Y., S. J. Slinger & H. S. Bayley. 1976. Influence of level and type of dietary protein, and of level of feeding on feed utilization by rainbow trout. J. Nutr. 106: 1547–1556.
Drury, D. E. & J. G. Eales. 1968. The influence of temperature on histological and radiochemical measurements of thyroid activity in the eastern brook troutSalvelinus fontinalis Mitchill. Can. J. Zool. 46: 1–9.
Gorbman, A. 1969. Thyroid function and its control in fishes pp. 241–274. In: W. S. Hoar & D. J. Randall (ed.) Fish Physiology, Volume II, Academic Press, New York.
Hilton, J. W., C. Y. Cho & S. J. Slinger. 1978. Effect of graded levels of supplemental ascorbic acid in practical diets fed to rainbow trout (Salmo gairdneri). J. Fish. Res. Board Can. 35: 431–436.
Ingbar, S. H. & K. A. Woeber. 1974. The thyroid gland. pp. 95–232. In: R. H. Williams (ed.) Textbook of Endocrinology, W. B. Saunders Co., Philadelphia.
Jackson, P., S. Lees, M. Pow, G. W. Willing & D. Watson. 1076. Radioimmunoassay kits for thyroid hormones. J. Clin. Path. 29: 902–907.
Leatherland, J. F., B. J. Barnett, C. Y. Cho & S. J. Slinger. 1980. Effect of dietary cholecalciferol deficiency on plasma thyroid hormone concentrations in rainbow trout,Salmo gairdneri (Pisces, Salmonidae). Env. Biol. Fish. 5: 167–173.
Leatherland, J. F., C. Y. Cho & S. J. Slinger. 1977. Effects of diet, ambient temperature, and holding conditions on plasma thyroxine levels in rainbow trout (Salmo gairdneri). J. Fish. Res. Board Can. 34: 677–682.
Milne, R. S. & J. F. Leatherland. 1978. The use of SeraluteR and TetraluteR for measurements of plasma triiodothyronine and thyroxine in salmonid fishes. Can. J. Zool. 56: 2242–2245.
Narayansingh, T. & J. G. Eales. 1975. The influence of physiological doses of thyroxine on the lipid reserves of starved and fed brook trout,Salvelinus fontinalis (Mitchill). Comp. Biochem. Physiol. 53: 399–405.
Pang, P. K. T. 1971. The effects of complete darkness and vitamin C supplement on the killifish,Fundulus heteroclitus adapted to sea water. I. Calcium metabolism and gonadal maturation. J. Exp. Zool. 178: 15–22.
Shaw, W., J. Powell, I. L. Hubert & F. W. Spierto. 1976. A comparison of the interference of fatty acids in the competitive binding radioassay and radio immunoassay for serum T4. Clin. Chim. Acta 73: 25–29.
Subcommittee on Fish Nitrition, Committee on Animal Nutrition, National Research Council, National Academy of Science, 1973. Nutrient Requirements of Trout, Salmon and Catfish.
Steel R. G. D. & J. H. Torrie. 1960. Principles and Procedures of Statistics. McGraw-Hill Book Co., New York. 000 pp.
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Leatherland, J.F., Cho, C.Y., Hilton, J.W. et al. Further studies on the effect of diet on serum thyroid hormone concentrations and thyroid histology in rainbow trout,Salmo gairdneri (Pisces, Salmonidae). Environ Biol Fish 5, 175–179 (1980). https://doi.org/10.1007/BF02391625
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DOI: https://doi.org/10.1007/BF02391625