Morphofunctional changes in the rat's liver of different ages after L-methionine administration

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

Effect of intermittent normobaric hypoxia on the morphological changes in the respiratory part of lungs in different seasons of the year

The purpose of this work was to study and compare the effect of intermittent normobaric hypoxia on the morphological and biochemical indices of the functional state and structure of the respiratory part of the lungs in the spring and autumn. The experimental rats were daily exposed to hypoxic gas mixture (12% oxygen in nitrogen) in intermittent mode: 15 minutes deoxygenation / 15 minutes reoxygenation for 2 hours. The duration of the experiment was 28 days. The histological preparations were made by the standard methods. The slides were photographed using a digital camera on the microscope «Nikon» (Japan). The morphometric analysis was performed on digital images with using the computer program "Image J". In the lung tissue was determined the concentration of total hydroxyproline and lipids. The results of our studies showed the seasonal differences in the effect of intermittent normobaric hypoxia on the morpho-functional state of respiratory part of the lungs. It can be related to the features of its activity in the spring and autumn. In spring, during a period of lesser activity of respiratory part of the lung, prolonged exposure to intermittent normobaric hypoxia slightly increases its functional activity. But in autumn, during a period of greater activity, it decreases. Thus, the use of intermittent normobaric hypoxia makes it possible to smooth seasonal differences in respiratory part of the lung activity

Role of CD45 Signaling Pathway in Galactoxylomannan-Induced T Cell Damage

Previously, we reported that Galactoxylomannan (GalXM) activates the extrinsic and intrinsic apoptotic pathways through an interaction with the glycoreceptors on T cells. In this study we establish the role of the glycoreceptor CD45 in GalXM-induced T cell apoptosis, using CD45+/+ and CD45−/− cell lines, derived from BW5147 murine T cell lymphoma. Our results show that whereas CD45 expression is not required for GalXM association by the cells, it is essential for apoptosis induction. In CD45+/+ cells, CD45 triggering by GalXM reduces the activation of Lck, ZAP70 and Erk1/2. Conversely, in CD45−/− cells, Lck was hyperphosphorylated and did not show any modulation after GalXM stimulation. On the whole, our findings provide evidence that the negative regulation of Lck activation occurs via CD45 engagement. This appears to be related to the capacity of GalXM to antagonize T cell activation and induce T cell death. Overall this mechanism may be responsible for the immune paralysis that follows GalXM administration and could explain the powerful immunosuppression that accompanies cryptococcosis

Morphofunctional state of the lungs respiratory part in normotensive and hypertensive rats after combined exposure to intermittent hypoxia and melatonin

Aim. The purpose of this work was to study and compare the combined effect of intermittent normobaric hypoxia (INH) and melatonin on the morphological and biochemical indices of the lungs respiratory part in Wistar and spontaneous hypertensive rats (SHR). Material and methods. The studies were conducted on 48 young male rats Wistar and SHR lines. The experimental rats were daily exposed to hypoxic gas mixture (12 % oxygen in nitrogen) in intermittent mode: 15 min deoxygenation / 15 min reoxygenation for 2 hours. Animals also received oral melatonin at a dose of 5 mg /1 kg of body weight once daily.Results. The sizes of alveolus were reduced, but their number and placement density were increased in SHR rats after a combined effect of INH and melatonin. The results showed a significant decrease of the interalveolar septum thickness and a tendency to decrease of the hydroxyproline concentration in the lung tissue of the experimental rats, regardless of their line.Conclusions. The 28-day combined effect of INH and melatonin increase the total alveolar surface area and reduce the amount of connective tissue in the lungs of experimental rats. These changes can improve the efficiency of the intrapulmonary gas exchange processes. </p

Seasonal features of the combined effects of intermittent normobabic hypoxia and melatonin on the thyroid gland morphofunctional state

The aim of this work is to compare the effect of the combination influence of dosed intermittent normobaric hypoxia and melatonin in different seasons of the year on the morphofunctional state of the rats’ thyroid gland.Material and methods. The study was carried out on 48 male rats of the Wistar line. The hypoxic gas mixture (12% O2 and 88% N2) was daily given to experimental animals in intermittent mode: 15 minutes deoxygenation / 15 minutes reoxygenation for 2 hours. Melatonin was administered orally in a dose of 5 mg / kg at10.00 a.m. The total duration of the experiment was 28 days. Histological preparations were prepared according to a standard methodic. Histomorphometry of the digital images of preparations was carried out using the computer program «Image J».Results. It was shown that the thyroid gland of rats reacted differently to the combined effects of intermittent hypoxia and melatonin at different seasons. So the signs of the gland activity were increased after influence of hypoxia and melatonin in spring. It was evidenced by a smaller area of follicles and colloid, a smaller internal diameter of the follicles and colloid-accumulation index, a greater height of the thyrocytes and follicular-colloid index, a smaller width of the interlobar, interlobular and interfollicular connective tissue interlayers compared to the control. The prolonged exposure to intermittent hypoxia and melatonin in autumn decreased the area and height of the follicular epithelium, increased the internal diameter of the follicles, decreased the follicular-colloidal index and increased the colloid-accumulation index. This indicated a decrease in the activity of the thyroid gland.Conclusions. Thus, in the spring, the morphofunctional activity of the thyroid gland is moderately increased, and in the autumn period, on the contrary, decreases.</p