EFFECT OF INTERVAL FASTING ON MORPHOLOGICAL CHANGES IN THE RAT THYROID GLAND OF DIFFERENT AGE

Author(s):  
R.V. Yanko ◽  
◽  
M.I. Levashov ◽  

Despite of the well-studied effect of interval fasting on the body, literature data on its infl uence on functional activity and, especially, on morphological changes in the thyroid gland are sporadic. The research results are often contradictory, which may be due to differences in experimental conditions. The aim of this study was to investigate the morphological changes in the rat’s thyroid gland of different ages, which were on interval fasting. The experiments were performed on 48 male Wistar rats aged 4 and 16 months. The experimental rats underwent interval fasting (1 day complete fasting / 2 days standard diet). Duration of experiment was 28 days. Thyroid tissue preparations were made according to standard histological methods. The morphometry was performed on digital images using a computer program Image J. It was found that the colloid area, the interior diameter of the follicles and colloid accumulation index were decreased in 4 and 16 month-old rats after interval fasting. The relative connective tissue area was also decreased in 16-month- old rats. But the follicular epithelium height, the follicular-colloidal index and the number of interfollicular islets were increased. The morphological changes of the thyroid gland tissue in 16-month-old experimental rats were manifested to a greater extent than in young animals. Thus, after exposure to interval fasting, morphological signs of activation of the thyroid gland synthetic activity in rats of different ages were observed. Key words: interval fasting, thyroid gland, morphometric indicators.

2021 ◽  
Vol 26 (2(49)) ◽  
pp. 89-97
Author(s):  
R. V. Yanko

Introduction: Despite the well-studied effect of alimentary deprivation on the body, the literature data on its effect on functional activity and, in particular, on morphological changes in the thyroid gland are single and often contradictory, which does not allow unambiguous conclusions. All this requires a more detailed study of the role and mechanisms of the impact of restricted nutrition on the thyroid gland. Aim: To investigate the effect of alimentary deprivation on morphological changes in the thyroid gland of young rats. Methods: The study was conducted on 24 male Wistar rats aged 3 months. Rats of all groups were in uniform conditions, on a standard diet. Animals of the experimental group, for 28 days, received a diet reduced by 30 %. Work with rats was carried out in accordance with the principles of the Declaration of Helsinki. Histological preparations were made from the central areas of the thyroid tissue according to the standard method. Using a digital camera, the micropreparations were photographed under a Nikon Eclipse E 100 microscope (Japan). Morphometry was performed using a computer program "Image J". Results: Histological analysis of the rat's thyroid gland affected by alimentary deprivation revealed that it had an unchanged physiological structure. The follicles were mostly of oval shape and of various sizes. Colloid in the follicles of experimental animals is of moderate density and contains numerous resorption vacuoles. Thyroid cells are of prismatic and cubic shape. It was found that in the thyroid gland of experimental rats the area of ​​follicles, colloid, their inner diameter decreases, the height of thyrocytes increases, the stereological resorption index increases and the colloid accumulation index decreases, the number of interfollicular islands increases. Also in experimental animals there was a decrease in the width of the interlobar and interfollicular connective tissue. Conclusion: In rats fed on a reduced diet, morphological signs of increased functional activity of the thyroid gland were found.


2022 ◽  
Vol 12 (1) ◽  
pp. 125-137
Author(s):  
Roman Yanko ◽  
Elena Chaka ◽  
Mikhail Levashov

Background: Literature data on the effect of methionine on functional activity and, especially, on morphological changes in the liver parenchyma in animals of different ages are sporadic, and research results are often ambiguous. Aim: The purpose of this work was to study and compare the morphofunctional changes in the liver of rats of different ages on prolonged administration of L-methionine. Material and Methods: The experiment was performed on 48 male Wistar rats of 3 and 15 months of age. Animals of the experimental group received L-methionine at a dose of 250 mg/kg body weight in addition to the standard diet, daily for 21 days. Histological preparations were prepared from liver tissue by a standard technique. Morphometry was performed on digital images using the computer program «Image J». Succinate dehydrogenase activity and protein concentration were determined in the suspension of hepatocyte mitochondria. Results: It was revealed that 21-day administration of L-methionine to rats led to hypertrophy of the hepatocyte nucleus, an increase in the nuclear-cytoplasmic ratio, the number of binuclear hepatocytes, and the nucleolus in the cell nucleus. The relative area of ​​the sinusoids network increased by 50% in 3-month-old animals. This indicated a better blood filling of the liver parenchyma. The increase in succinate dehydrogenase activity and protein concentration was revealed in the suspension of hepatocyte mitochondria of the experimental rats. This indicated an increase in the mitochondria energy potential and protein-synthetic activity. Conclusions: The administration of prophylactic doses of methionine to healthy rats leads to the appearance of pronounced morphological and functional signs of increased activity of hepatocytes. The severity of this effect has a distinct age-dependent character. In young rats, it is more pronounced than in mature rats. The results of the study are important for practical medicine when using methionine for therapeutic and prophylactic purposes.


2021 ◽  
Vol 25 (3 (99)) ◽  
pp. 124-131
Author(s):  
O. Fedosieieva

The purpose of the work was to establish the features of Fox-1 expression and distribution in the parenchyma of the thyroid gland of rats in the postnatal period of ontogeny in the norm and after intrauterine action of dexamethasone.Material and methods: thyroid gland of rats (162 animals) of the Wistar line at the age from 1 to 14 days of postnatal development. Experimentally, the animals were injected intrauterinely with a solution of dexamethasone at a dose of 0.05 ml at a dilution of 1:40 on the 18th day of the dated pregnancy. The material was examined using a set of methods of morphological studies (production of histological serial sections, survey microscopy, morphometry, immunohistochemistry and statistical processing).Results of the research. In the thyroid glands of neonatal prenatal dexamethasone, the parenchyma was well developed and consisted of hollow colloid-type follicles and single colloid-type microfollicles, and a bright cytoplasmic reaction with Fox-1 antibodies was observed throughout the organ parenchyma. In the thyroid glands of animals of the 3rd day of life, morphological changes occurred in all groups of the experiment. In animals of the experimental group, hollow follicles of colloidal type of small, medium and large diameter were chaotically visualized throughout the body, and large follicles of irregular shape with immunohistochemical weak or negative reaction with Fox-1 antibodies in thyrocytes and lumen without colloidal evidence, which detected a decrease in the specific synthetic activity in these thyrocytes. On day 7 in the experimental group in the flattened thyrocytes of overstretched follicles, the expression of Fox-1 was present only in the apical part. On days 11-14 of postnatal development in the thyroid glands of rats experimentally prenatally exposed to dexamethasone in the wall of large follicles with flattened epithelium began extrafollicular proliferation of thyrocytes on the background of visualization in the lumen of these follicles desquamated cells. Intensive perinuclear and cytoplasmic Fox-1 positive reaction was present in extrafollicular proliferating thyrocytes.Conclusions. 1. The detected changes in the first day of life in the thyroid gland of rats indicated that prenatal administration of dexamethasone affects the intensification of differentiation not only structural and functional units - follicles, but also a specific synthetic intracellular apparatus of thyrocytes, judging by the intensification of Fox-1. Thus, immature pre-mRNA is converted into mature mRNA, from which thyroid proteins, in particular thyroglobulin, are translated. By the time of birth, this process in the experimental group reaches a significant development, covering the entire parenchyma of the gland. 2. In rats prenatally receiving dexamethasone, the period of lactation was characterized by intense structural changes in the thyroid gland, in particular intracellularly in thyrocytes of monolayer flattened epithelium, the expression of Fox-1 antibodies was sharply reduced, which was then replaced by a bright cytoplasmic reaction in proliferative clusters and follicles of colloidal type of secretion, which is an adaptive-compensatory mechanism of intracellular enhancement of proliferation of synthesizing organelles in response to the restructuring of a significant number of existing follicles by hypofunctional type, aimed at maintaining normal levels of thyroid function.


2021 ◽  
Vol 25 (1-2) ◽  
pp. 31-35
Author(s):  
O.I. Ryabukha

The structure of endocrine morbidity is characterized by a significant spread of thyroid pathology. The insufficient efficacy of inorganic iodine drugs poses the problem of search for new means for iodine deficiency treatment and prevention. Given the progressive aging of the population in economically developed countries, the purpose of the study was to clarify the effect of organic iodine on the features of absorption and elimination of radioactive iodine from the thyroid glands of variously aged rats in the conditions of iodine deficiency in the diet. The study was performed on nonlinear white male rats in two series of studies that were kept on iodine-deficient isocaloric starch-casein diet for 60 days: the first series included two groups of old rats weighing 0.400-0.450 kg, the second series – two groups of sexually immature rats weighing 0.060-0.090 kg. There were 5 rats in each group. In animals of the experimental groups in each series, 10% of casein in the diet was replaced with organic iodine, which came with iodine-protein preparation from the red Black Sea algae Phyllophora nervosa. The functional state of the thyroid gland was studied using the Sodium Iodide Na 131 I Injection drug. The dosimetry was performed using the STS-6 Geiger-Muller Detector. Radioindication of the thyroid gland was carried out after subcutaneous administration of 0.1 ml of 131I solution at the following time intervals: 0.5, 1, 2, 4, 6, 8, 10, 12, 24, 48, 72, and 96 hours after administration of 131I. The study results were presented as a percentage of the radioiodine dose administered, adjusted for natural radioactivity background and the radioactive decay of the drug. It was found that in the iodine deficiency conditions, the thyroid glands of old rats have higher rates of radioiodine absorption and a lower rate of its excretion than the glands of immature rats, which indicates their lower iodine reserve and greater liability to iodine deficiency pathology. Intake of organic iodine regardless of the rats’ age is accompanied by a decrease in radioiodine accumulation and acceleration of its excretion from the thyroid gland, which indicates a decrease in functional stress, but the glands of older rats absorb more iodine and excrete it more slowly, indicating less effective correction of iodine deficiency with age. Reduced functional activity of the thyroid glands in old rats can be used as a sensitive changes marker for the in-depth study of thyrotropic and thyroid disrupting effects.


Author(s):  
Nishikanta Verma ◽  
Samuel Devanesan Abishegam ◽  
Abdul Razak Bin Haji Ahmad

<p class="abstract">An ectopic thyroid is a rare occurrence with a majority of ectopic thyroid tissue located in the lingual region or in the midline. The abnormal sites represent developmental defects in migration from the floor of the primitive foregut at the foramen caecum of the tongue to the final pre-tracheal position of the gland. A few cases of ectopic thyroid tissue have also been reported from sites seemingly unrelated to the normal development of the thyroid gland.  We report a case of ectopic thyroid in the external ear canal, which presented as a small reddish mass in the external ear canal. To the best of our knowledge, this is the first such reported case in literature and adds to the body of knowledge in such cases. Although such a finding is exceedingly rare, the authors recommend routine histopathology in all cases of polyps in the external canal and standard investigation for the status of the residual thyroid gland via isotope scans, ultrasonography or thyroid function tests.</p>


Author(s):  
O. Iefimenko ◽  
O. Savchenko ◽  
T. Falalyeyeva ◽  
O. Kyric ◽  
M. Spivak

We have studied the effect of nanocrystalline cerium dioxide (NCD) on the morphological state of the gastric mucosa and colon in rats of different ages. It was found the degenerative changes and dysregeneration (violation the ratio of value of major and parietal cells), atrophic or hyperplastic changes. NCD restored the processes of differentiation and proliferation of epithelial cells of gastric glands. In the control group of old rats mucosa of the colon was focal thinner, the cells had degenerative changes, it was observed the change in nuclear-cytoplasmic ratio of cells, were found foci of infiltration of lymphocytes, macrophages, plasma cells. NCD in old rats caused a decrease in the number of cells in a state of degeneration and apoptosis, increased proliferative activity of cells increased the number of goblet cells. Thus, NCD restored morpho-functional structure of the mucous of the stomach and colon.


1989 ◽  
Vol 37 (5) ◽  
pp. 691-696 ◽  
Author(s):  
Y Uchiyama ◽  
T Watanabe ◽  
M Watanabe ◽  
Y Ishii ◽  
H Matsuba ◽  
...  

To localize cathepsins B, H, and L in follicular cells of rat thyroid gland, we applied immunocytochemistry to the thyroid tissue using their respective monospecific antibodies. On serial semi-thin sections, cathepsins B, H, and L were localized in granules of various sizes located throughout the cytoplasm, whereas T4 was detected in larger granules located in the apical and supranuclear regions. By electron microscopy, cathepsins B, H, and L were localized in large less-dense granules (so-called colloid droplets) and in dense bodies of various sizes, whereas T4 was localized more intensely in large less-dense granules than in smaller dense bodies. By double immunostaining using an immunogold method, cathepsins H and B or L were co-localized in the same cytoplasmic granules. Moreover, immunoblotting demonstrated that proteins similar to cathepsins B, H, and L in the liver are present in the thyroid gland. These results suggest that cathepsins B, H, and L participate not only in degradation of thyroglobulin but in maturation of thyroid hormones, although it remains unknown whether all of them participate in the maturation process.


1969 ◽  
Vol 45 (2) ◽  
pp. 197-205
Author(s):  
S. Y. CHOW ◽  
D. M. WOODBURY

SUMMARY [14C]Inulin, 35SO42- and 36Cl- spaces, 131I- thyroid: serum (T:S) ratio, histological measurements of follicles and electrolyte content of the thyroid gland were determined in male rats 3–17 weeks of age. The thyroid [14C]inulin space of animals of different ages was not significantly different. The thyroid 35SO42- space, however, varied with age. The youngest rats had the largest 35SO42- space. Histological measurements indicated that in the thyroid follicles the epithelial cells were much thinner and the luminal volume was much larger in the younger rats than in older animals. In the older rats, the 35SO42- space was equal to the sum of [14C]inulin (stromal) and the histologically determined luminal spaces. In the younger animals, although the 35SO42- space was larger than in the older animals, it was still not large enough to equal the sum of the volumes determined by the [14C]inulin and the direct histological measurements of the lumen. This is due to the high colloid content in the follicular lumen of the young rats. The lower thyroid 131I- T:S ratio in younger rats also indicated that the thyroid gland was less active than in older animals. The volume of distribution of thyroid Cl- calculated from the chemically determined data of the plasma and of the thyroid tissue concentrations of rats of different ages was the same as that determined by 36Cl-.


1997 ◽  
Vol 248 (2) ◽  
pp. 251-258 ◽  
Author(s):  
V.S. Usenko ◽  
I.N. Kornilovskaya ◽  
V.V. Lizogubov ◽  
E.O. Apostolov ◽  
E.A. Gubkina ◽  
...  

Introduction. The protection of the body against external and internal antigenic factors is executed with the help of the primary cellular and secondary resistance links. Excessive activation of adaptation reactions leads to the formation of various pathologies of inflammatory nature. Changes in the immune responses occur at all ontogenesis stages. In the present study, we conduct the experiment of induced peritonitis in animals of different ages in order to investigate more accurately adaptive responses of the immune system during inflammation. Objectives. The aim of our research was to study changes in the indicators of adaptive humoral immunity, levels of immunoglobulin A and circulating immune complexes, phagocytic activity of neutrophils and the disruption of enzymes activity, which provide the phagocyte function in the NST test on the model of induced peritonitis in animals of different ages. Materials and methods. The studies were performed on 200 white male rats. They were divided into a control group and the experimental rats, 3- and 22-month-old ones. Acute inflammation and dysbiosis in the small intestine were caused by intraperitoneal injection of lipopolysaccharide obtained from Escherichia coli strain. The material for the study was serum and blood elements of experimental animals. Results. The levels of immunoglobulin A in the blood serum of 3 and 22-month-old rats with the inflammation model were reduced in comparison with this index in control group animals. The content of the CIC in the rats blood serum of both age groups was significantly higher in comparison with the control group. All the studied indices of neutrophils phagocytic activity in the 22-month-old animals with the inflammation model were lower than in the control rats of this age. In the 3-month-old rats with the inflammation model, the index of phagocytosis completeness was significantly lower in comparison with the control group. The reduction in the reserve capacity of phagocytic cells was higher in the 22-month-old animals. An increase in the neutrophils metabolic activity and a decrease in their metabolic reserve in 3 and 22-month-old rats with the inflammation model were revealed in comparison with the parameters of the control groups. Conclusions. The results of the study indicate presence of violation of the primary cellular and secondary humoral immunity during the aging of the body and decrease in the adaptive responses of the immune system during inflammation due to an increase in antigenic effects.


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