Morphofunctional characteristics of hepatocytes after exposure to intermittent normobaric hypoxia in normotensive and hypertensive rats

Abstract

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.