There are only few studies in which the effect of intermittent normobaric hypoxia on the liver status in animals and people with arterial hypertension has been investigated. That’s why it’s necessary to carry out these studies in animals with high blood pressure. The purpose of this work was to carry out comparative studies of the effect of dosed intermittent normobaric hypoxia on the morphofunctional state of hepatocytes of normotensive (line Wistar) and spontaneously hypertensive (line SHR) rats, age 4 months. 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. Histological, morphometric and biochemical research methods were used. 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 using the computer program "Image J". The activity of cytochrome oxidase and succinate dehydrogenase enzymes in a suspension of hepatocytes mitochondria was determined by the method of R. S. Krivchenkov. An increase was observed in the size of hepatocytes and their nucleus, in the number of binuclear hepatocytes and nucleolus in the liver of both experimental lines of animals after exposure to intermittent normobaric hypoxia. The distance between adjacent nuclei of hepatocytes decreased. Cytochrome oxidase activity in a suspension of mitochondria increased. These morphological changes took place in the liver parenchyma of the both experimental lines of rats. But they were more pronounced in the liver of rats of the Wistar line than in the SHR line. Our data indicated that dosed normobaric hypoxia had a one-way, stimulating effect on the morphofunctional activity of hepatocytes, but the severity of this effect in rats of different lines was not the same. The obtained data can have not only theoretical value, but also be of some practical interest when using intermittent normobaric hypoxia for medical and health purposes in patients with impaired liver function and arterial hypertension.
BACKGROUND: The problem of diagnosis, treatment and prevention of fat liver disease (FLD) is one of the actual problems of modern medicine. In this regard, the need for the creation of reliable experimental models of the FLD, which would be as close as possible to the pathogenetic patterns of the development of this disease in humans.AIM: To create an experimental model of FLD and compare the efficiency of its reproduction in rats of different ages.MATERIALS AND METHODS: The study was conducted on male Wistar rats, whose ages at the beginning of the experiment were 3 and 18 months. Control animals were fed a standard diet. The experimental rats were kept on a diet with excess fat (45 %) and carbohydrates (31 %) for 12 weeks. The liver tissue samples were taken for morphological studies of FLD. Histological preparations were made according to the standard technique. Morphometry on digital images of micropreparations was conducted using the computer program «IMAGE J». The concentration of lipids, cholesterol, and triglecerides in the liver tissue was determined, and the concentration of ALT in the blood serum was determined. To assess the biophysical properties of the liver tissue, the method of multifrequency bioimpedance measurement was used.RESULTS: The transfer of animals to a high-calorie diet developed by us led to the development of FLD. This was evidenced by an increase of the liver mass, its pale shade and soft consistency. Morphometric signs of FLD were also revealed. Hypertrophy of hepatocytes was observed with a simultaneous decrease in the nuclear-cytoplasmic ratio; accumulation of numerous lipid inclusions in the cytoplasm and the appearance of large lipid droplets replacing the voids of dead hepatocytes. The number of binuclear hepatocytes and nucleolus in the nucleus, the relative area of the sinusoid network were decreased. An increase in the concentration of lipids, cholesterol and triglecerides in the liver tissue of experimental rats, as well as the activity of ALT in the blood serum, was observed. Changes in the bioimpedance measurements of the liver tissue also indicated the development of severe fatty degeneration of the liver in both young (to a greater extent) and old rats.CONCLUSION: The model of FLD we have advanced based on a combined (fat-carbohydrate) high-calorie diet. It leads to the development of pronounced morphological, biochemical and biophysical signs of this pathology in all experimental rats. The most pronounced manifestations of FLD are observed in young animals.
The effect of hypercapnia for resistance to fruit flies hyperthermic stress, life expectancy at alimentary and water deprivation and spontaneous locomotor activity. Canton-S and Oregon-R test Drosophila lines were divided into low and high are resistant to the action of carbon dioxide and contained in hypercapnic gas medium (5 % CO2) for seven generations. Under the influence of hypercapnia increased resistance to fruit flies hyperthermic stress. Life expectancy line Drosophila Canton-S high are resistant to the action of CO2 alimentary conditions of water deprivation increased 5 % and time of extinction of a half of individuals to 19 % compared with the control. In Drosophila line Oregon-R low and high are resistant to the action of CO2. the average life expectancy had a tendency to decrease i7-8 % compared with the control. It is shown that the spontaneous motor activity of both drosophila lines highly resistant to CO2 was higher compared to the low resistant. The number of flies with a positive phototaxis after adaptation to hypercapnia reduced in Drosophila all the experimental groups.
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 57 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.
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