Thymic Fatty Degeneration in the Vertebrate Animals and Humans
https://doi.org/10.18499/2225-7357-2020-9-2-76-83
Abstract
The aim of the study was to compare features of fatty degeneration of the thymus in humans and vertebrate animals living in the natural and anthropogenic environment.
Material and methods. This was a comparative morphological study. For the first time, the methods of light microscopy were applied to compare the thymus in humans and vertebrates belonging to four classes: Amphibia, Reptilia, Aves, Mammalia.
The results of the study evidence the absence of fatty degeneration of the thymus in the vast majority of animals living in the natural environment. Owing to the specific features of biology, an insignificant amount of adipose tissue (0.38±0.041%) in the area of interlobular septa appears only in the thymus of a white-breasted hedgehog. There is no fat replacement of the lymphoid tissue of the thymus in the hedgehog, since fat cells remain separated from the lymphocytes and reticulo-epithelial stroma by the connective tissue fibers of the interlobular septa. In vertebrates under vivar conditions, as well as in humans, the severity of fatty degeneration increases tenfold due to the effects of physical inactivity. It was found that in the second period of maturity, the area occupied by the adipose tissue in the thymus of mature American mink reaches 3.07±0.68%, in an outbred rat – 28.4±4.1% and in humans – 39.15±6.65%. The early terms of the onset of fatty degeneration and the greatest severity of this phenomenon in the thymus of a human are associated not only with the influence of hypokinesia and excessive intake of calories, but also due to a complex of other adverse effects that are found in abundance in an anthropogenic environment.
Conclusion. Thus, fatty degeneration is not an obligate effect of age-related involution of the lymphoid system, but most likely results from the influence of specific conditions of existence.
About the Author
V. Ya. Yurchinskii
Smolensk State University,
Smolensk State Medical University
Russian Federation
ul. Przheval'skogo, 4, Smolensk, 214000, Russian Federation
Russian Federation
ul. Przheval'skogo, 4, Smolensk, 214000, Russian Federation
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Review
For citations:
Yurchinskii V.Ya. Thymic Fatty Degeneration in the Vertebrate Animals and Humans. Journal of Anatomy and Histopathology. 2020;9(2):76-83. (In Russ.) https://doi.org/10.18499/2225-7357-2020-9-2-76-83
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