Abstract
Literature data on the effect of interval fasting on functional activity and, especially, on morphological changes in the thyroid gland are sporadic. And the available information about its effect on the morphological and functional state of the thyroid gland is often contradictory. The aim of the work — to study the morphological changes in the thyroid gland of adult rats after exposure to interval fasting. Material and methods. The study was conducted on 24 male Wistar
rats at the age of 15 months. The experimental rats underwent interval fasting (1 day complete fasting / 2 days standard diet). Access to water was free. Duration of experiment was 28 days. Rats were decapitated under mild ether anesthesia. Work with animals was carried out in accordance with the principles of the Helsinki Declaration. From thyroid tissue preparations were made according to standard histological methods. Micrographs of the gland were taken with a digital camera. Gland morphometry was performed on digital images using a computer program Image J. Results. The thyroid gland of rats, after the influence of interval fasting, retained the physiological structure, with a clear division into the central and peripheral zones. The follicles in it were of different sizes and had an oval and elongated shape. The colloid of the thyroid follicles of the experimental animals was of moderate density, often had a «foamy» character due to the presence of resorption vacuoles. The thyroid cells of experimental rats had a cubic and prismatic shape. It was found that in the thyroid gland of adult rats, after influence the interval fasting, decreased the size of the follicles and colloid, the inner diameter of the follicles, increased the thyroid cell height, the follicular-colloid index and decreased the colloid accumulation index, increased the number of resorption vacuoles in the colloid of follicles and the amount of interfollicular islets. In the glands of these animals were revealed a decreased in the relative area of the stroma and stromal-parenchymal index, as well as a decreased in the width of the interlobar, interlobular, and interfollicular connective tissue. Conclusion. The effect of interval fasting has morphological signs of activation of the thyroid gland synthetic activity in adult rats. The data obtained may be of interest for practical medicine in deciding on the appointment of interval fasting to people with reduced thyroid function.
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