THE COMBINED EFFECT OF INTERMITTENT NORMOBARIC HYPOXIA AND MELATONIN ON THE MORPHOLOGICAL CHANGES OF THE SPONTANEOUSLY HYPERTENSIVE RATS PANCREAS
The aim of the study was to investigate the morphological changes in the pancreas of spontaneously hypertensive animals after the combined effect of intermittent normobaric hypoxia (INH) and melatonin. Materials and methods. The study was carried out in spring on 24 spontaneously hypertensive male rats (SHR line). The experimental animals were daily given a hypoxic gas mixture (12 % oxygen in nitrogen) in an intermittent mode: 15 min deoxygenation/15 min reoxygenation for 2 hours. The same rats were daily a dministered orally with exogenous melatonin at 10.00 at a dose of 5 mg/kg. The duration of the experiment was 28 days. Histological preparations were prepared according to a standard procedure. Morphometry of the digital images of preparations was performed using the computer program ImageJ. Results. Based on changes in morphometric parameters (reduction in the size of acini, exocrinocytes, height of the epithelium), it can be assumed that the combined effect of INH and melatonin reduces the activity of the exocrine function of the pancreas. In the endocrine part of the pancreas of experimental animals morphological signs of its activation were noted: the linear dimensions of the Langerhans islets, the number and the density of their endocrine cells increased. Experimental animals also showed a decrease in the width of interlobular and interacinar interlayers of connective tissue, which can be considered as a manifestation of the mechanism of structural adaptation that facilitates the transport of oxygen and nutrients to the parenchymal elements of the pancreas. Conclusions. The combined effect of intermittent normobaric hypoxia and melatonin leads to the appearance of morphological signs of a decrease in the activity of the exocrine part of the pancreas in hypertensive rats. At the same time, the activity of the endocrine gland function in these animals increased.