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The effect of a nutritionally-balanced cassava (Manihot esculenta Crantz) diet on endocrine function using the dog as a model 2. Thyroid

Published online by Cambridge University Press:  09 March 2007

Beryl P. Kamalu
Affiliation:
Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka, Nigeria
Julius C. Agharanya
Affiliation:
Department of Chemical Pathology, College of Medicine, University of Nigeria, Enugu Campus, Nigeria
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Abstract

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Growing dogs were divided into three groups and were fed on nutritionally-balanced diets. Control dogs were fed on a rice diet, the cassava (gari) group ate a diet in which gari provided the carbohydrate source, while the rice + cyanide group consumed the rice diet to which hydrocyanic acid (equivalent to that present in gari) was added. Each group consumed its diet for 14 weeks, during which plasma thiocyanate concentration and total serum triiodothyronine (T3) were monitored. At the end of the experiment the concentrations of the plasma free amino acids phenylalanine and tyrosine, the thyroid weights and histology were determined. While plasma thiocyanate remained undetectable in control dogs, animals consuming both gari and rice + cyanide generated significant amounts. In the control dogs and the gari group, total serum T3 increased 40 and 38.8 % respectively from the basal level by the end of the period (P < 0.02). In contrast there was a decrease in T3 by 36% in the dogs fed on rice+cyanide (P < 0.05). This group also showed significant thyroid enlargement and a histological picture consistent with parenchymatous goitre, whereas the gari group was essentially normal. The relatively low mean thyroid weight, the rise in total serum T3 level and the normal histological appearance of the gland indicate that dogs that consumed the gari diet were essentially normal with respect to their thyroid function, in spite of their high blood thiocyanate content. In contrast, dogs that consumed rice with cyanide suffered from hypothyroidism and goitre. It is suggested that the gari diet, despite generating thiocyanate endogenously, when taken in a nutritionally-balanced diet with high-quality animal protein, has no deleterious effects on thyroid function.

Type
Nutritional Effects on Endocrine Function
Copyright
Copyright © The Nutrition Society 1991

References

REFERENCES

Baker, M. H. (1936). The blood cyanates in the treatment of hypertension. Journal of the American Medical Association 106, 762767.CrossRefGoogle Scholar
Bayoumi, R. A., Taha, T. S. & Saha, N. (1988). Study of possible genetic predisposition to endemic goitre among the Fur and Baggara tribe of the Sudan. Human Heredity 38, 811.Google Scholar
Bourdoux, P., Delange, F., Gerard, M., Mafuta, M., Hanson, A. & Ermans, A. M. (1978). Evidence that cassava ingestion increases thiocyanate formation: a possible etiologic factor in endemic goitre. Journal of Clinical Endocrinology and Metabolism 46, 613621.Google Scholar
Cliff, J., Lundqvist, P., Martensson, J., Rosling, H. & Sorbo, B. (1985). Association of high cyanide and low sulphur intake in cassava-induced spastic paraparesis. Lancet ii, 12111213.Google Scholar
Cosby, E. L. & Summer, J. B. (1945). Rhodanese. Archives of Biochemistry 7, 457460.Google Scholar
Delange, F., Bourdoux, P., Colinet, E., Courtois, P., Hennart, P., Lagasse, R., Mafuta, P., Seghers, P., Thilly, C., Vanderpas, J., Yunga, Y. & Ermans, A. M. (1982). Nutritional factors involved in the goitrogenic action of cassava. In Cassava Toxicity and Thyroid: Research and Public Health Issues. Proceedings of a Workshop, Ottawa [Delange, F. and Ahluwalia, R., editors]. International Development Research Centre Monograph 207e, pp. 1726. Ottawa: International Development Research Centre.Google Scholar
Delange, F., Van der Velden, M. & Ermans, A. M. (1973). Evidence of an antithyroid action of cassava in man and animals. In Chronic Cassava Toxicity. Proceedings of an Interdisciplinary Workshop, London. [Nestel, B. and MacIntyre, R., editors]. International Development Research Centre Monograph 0103, pp. 147151. Ottawa: International Development Research Centre.Google Scholar
Ekpechi, O. L. (1967). Pathogenesis of endemic goitre in eastern Nigeria. British Journal of Nutrition 21, 537545.CrossRefGoogle ScholarPubMed
Ekpechi, O. L., Dimitriadou, A. & Fraser, R. (1966). Goitrogenic activity of cassava (a staple Nigerian food). Nature 210, 11371138.CrossRefGoogle ScholarPubMed
Food and Agriculture Organization (1970). Amino acid content of foods and biological data on proteins. Nutritional Studies No. 24, Rome: FAO.Google Scholar
Frakes, R. A., Sharma, R. P., Willhite, C. & Gomez, G. (1986). Effect of cyanogenic glycosides and protein content in cassava diets on hamster prenatal development. Fundamental Applied Toxicology 7, 191198.CrossRefGoogle ScholarPubMed
Giesecke, D. (1985). Species differences relevant to nutrition and metabolism research. In Clinical Nutrition and Metabolic Research. Proceedings of the 7th Congress of the European Society of Parenteral and Enteral Nutrition, Munich, (Dietze, G., Griinert, A., Kleinberger, C. and Wolfram, C., editors) pp. 311328. Basel: Karger.Google Scholar
Kamalu, B. P. (1991). The effect of a nutritionally-balanced cassava (Manihot esculenta Crantz) diet on endocrine function using the dog as a model 1. Pancreas. British Journal of Nutrition 65, 365372.Google Scholar
Langer, P. (1966). Antithyroid action in rats of small doses of some naturally-occurring compounds. Endocrinology 79, 117122.Google Scholar
Miller, M. E., Christensen, G. C. & Evans, H. E. (1964). Anatomy of the Dog. Philadelphia: W. B. Saunders Co.Google Scholar
Nwokolo, C., Ekpechi, O. L. & Nwokolo, U. (1966). New foci of endemic goitre in eastern Nigeria. Transactions of the Royal Society of Tropical Medicine and Hygiene 60, 97108.Google Scholar
Osuntokun, B. O. (1970). Cassava diet and cyanide metabolism in Wistar rats. British Journal of Nutrition 24, 797800.Google Scholar
Sihombing, D. T. M., Cromwell, C. L. & Hays, V. W. (1971). Effect of added thiocyanate and iodine to corn-soybean meal diet on performance and thyroid status of pigs. Journal of Animal Science 33, 1154.Google Scholar
Udeozo, I. O. K. & Agharanya, J. C. (1986). Serum thyrotropin and thyroid hormone levels in normal subjects and those living in endemic goitre areas of Obudu, Nigeria. West African Journal of Medicine 5, 209214.Google Scholar
Van der Velden, M., Kinthaert, J., Orts, S. & Ermans, A. M. (1973). A preliminary study on the action of cassava on thyroid iodine metabolism in rats. British Journal of Nutrition 30, 511517.Google Scholar