Abstract
Alimentary obesity is accompanied by a disorder of all types of metabolism, a decrease in the function of most organs, including the thyroid gland. In this regard, the relevance of research and development of new effective methods of prevention of thyroid function disorders in obesity is increasing. One such method may be the use of the essential amino acid tryptophan. The aim is to investigate the effect of L-tryptophan on histo-morphological changes in the thyroid gland of rats with food-induced obesity. Material and methods. The study was conducted on male Wistar rats, aged 6 months. Control animals (group 1) were on a standard diet. Experimental rats of the group 2 were fed a diet with an excess of fat (45%) and carbohydrates (31%) for 12 weeks. Experimental animals of the group 3, in addition to the high-calorie diet, additionally received L-tryptophan in a dose of 80 mg/kg of body weight. Histological preparations were made from thyroid gland tissue. Morphometry was performed using the computer program «ImageJ». Results. It was found that the stay of rats on a high-calorie diet led to the appearance of pronounced histomorphological signs of thyroid hypofunction. Intensive processes of colloid resorption and reduction of its area were observed in the gland. Empty follicles were often visualized. Thyrocytes acquired a prismatic shape. Thyroid hyperplasia was observed, which led to an increase in its size. In the thyroid gland of rats of the group 3, a smaller mass of the gland, larger sizes of follicles, colloid, follicular epithelium, a smaller follicular-colloid index and a stereological resorption index, a smaller amount of stroma in the gland compared to animals that received only a high-calorie diet were found. Also found that the administration of L-tryptophan reduced the intensity of visceral fat accumulation. Conclusion. Therefore, the administration of Ltryptophan to rats has protective properties on the thyroid gland and helps to reduce the degree of obesity. The obtained data have practical interest when using tryptophan and its derivatives to prevent the development of disorders of the thyroid gland functioning in case of alimentary obesity.
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