Study of the Functional State of Cardiac Mitochondria in Inbred Mice with Type 2 Diabetes Mellitus

The origin of diabetes mellitus, one of the most common metabolic diseases in the developed world, is associated with impaired insulin secretion or cell resistance to the effect of this hormone (type I and type II diabetes, respectively). In both cases, a common pathological change is an increase in blood glucose level, hyperglycemia, which can eventually lead to serious damage to organs and tissues of the body. Mitochondria are believed to be one of the main targets of diabetes at the intracellular level. In this study, we investigated the functional state of the mitochondria of the heart of inbred mice of the C57BL/Ks–db+/+m line carrying the recessive diabetes-db gene (diabetic mice). Histological analysis of the left ventricle of the heart of diabetic and control mice was performed. In the heart tissue samples of diabetic mice, an increase in the intensity of eosin staining was observed, which implies damage to the structure of cytoplasmic proteins. In addition, it was shown that respiratory control and Ca²⁺ capacity in the mitochondria of diabetic mice decreased compared to controls. Changes in mitochondrial dynamics and mitophagy under these conditions were investigated.