Age peculiarities of morphological changes in the rats heart at alloxan diabetes

[GW30-e0011]

Authors: Yarmolenko Olga, Bumeister Valentyna, Prykhodko Olga, Demikhova Nadiia, Bumeister Lina, Khotyeev Yegor, Sumy State University

OBJECTIVES Diabetes mellitus is one of the most common non-communicable diseases. Today, more than 382 million people with diabetes live on the planet. The dynamics of development is increasing every year. Diabetes mellitus is one of the main causes of cardiovascular pathologies. The purpose of our work was to establish the age-old peculiarities of the effect of alloxan diabetes on the heart of rats. The features of changes in internal organs are studied on experimental animal models in order to improve the methods of correction of adverse effects of diabetes mellitus on the body and, in particular, on the heart. One of the inductors of diabetes is alloxan.

METHODS The study was performed on 12 mature and 12 young white male rats, divided into two groups: control and experimental (6 in each). Animal retention and experiments were carried out in accordance with the requirements of the “General Ethical Principles of Animal Experiments”, adopted by the First National Congress on Bioethics (Kyiv, 2001). Animals of the experimental group administered once daily alloxan intraperitoneally at a dose of 40 mg/kg. From the 7^th to the 10^th day after the administration of alloxan, the level of glucose in the blood that was steadily elevated was measured. One month after the induction, the animals were withdrawn from the experiment with an anesthetized lung of decapitation. Hearts were digested according to the method of Avtandilov, separately weighed parts of the heart behind Muller. For histological examination, the ventricles were fixed in a 10% neutral formalin solution over the course of the day, dehydrated in alcohols of increasing concentration, and poured into paraffin. The sections of the myocardium were stained with hematoxylin-eosin and studied using a light microscope Olympus BH-2.

RESULTS Under conditions of alloxan diabetes in mature rats there is an increase in the heart mass by 41.09% (P<0.0001), left ventricle is 56% (P><0.0001), right ventricle is 31.46% (P><0.0001), the left ventricle area was 31.77% (P><0.0001), right ventricle 45.89% (P=0.0008). Atrial weight decreases by 64% (P><0.0001), the ventricular index is 14.94% (P=0.0014), the planimetric index is unreliable. Histologically, the polymorphism of nuclei of cardio-myocytes, local disorientation of muscle fibers and their cytolysis were revealed. Spacing gaps are expanded (stromal edema). Vessels of uneven filling: in some fields, the vessels are empty, in others – the aggregation of erythrocytes in vessels, capillary hyperemia, edema around the vessels. In young rats, an increase in left ventricular mass is observed at 33.48% (P=0.0327), left ventricular area is 18.22% (P=0.0061), right ventricle is 20% (P=0.0287). Atrial weight decreases by 38.78% (P=0.0035), ventricular index is 15.19% (P=0.0036). Other indicators are unreliable. Histologically – the polymorphism of the nuclei of cardiomyocytes, the disorientation of muscle fibers. Unidirectional contents of the vessel: in some fields the vessels are empty, in others the aggregation of red blood cells.

CONCLUSIONS In alloxan diabetes, an increase in the mass of the heart with an overwhelming left ventricular hypertrophy, cardiomyocytes and vascular disorders in the myocardium of experimental animals was detected. The violations of the structural components of the wall of the heart are detected. This indicates a low functional activity of the heart, which leads to cardiovascular pathologies.