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Evaluation of the T-system of Rat Cardiomyocytes during Early Stages of Streptozotocin-Induced Diabetesстатья
- Авторы: Kubasov I.V., Bobkov D.E., Stepanov A.V., Sukhov I.B., Chistyakova O.V., Dobretsov M.G.
- Журнал: Russian Journal of Physiology
- Том: 106
- Номер: 9
- Год издания: 2020
- Первая страница: 1098
- Последняя страница: 1108
- Аннотация: Disorganization of the T-system of cardiomyocytes is considered an early and critical step in the development of Diabetic Cardiomyopathy (DCM). To test this suggestion, male Wistar rats were injected with streptozotocin (STZ, 30 or 45 mg/kg) and studied one month later. STZ-rats that developed and maintained hyperglycemia (random blood glucose > 11 mM) were designated as hyperglycemic (STZ-HG) rats, while the remaining STZ-rats – as normoglycemic (STZ-NG) animals. The structural integrity of the T-system was investigated using an analysis of confocal images of the left ventricle (LV) sub-epicardium of isolated hearts, stained with the Di-8-ANEPPS. In control, T-system was organized into regular networks of t-tubules aligned with Z-discs of cardiomyocyte’s sarcomeres. Accordingly, the frequency distributions of intervals between neighboring t-tubules (INT, measured along the major cell axis) peaked at a 2 µm value with not more than 21% of INT (per cell) exceeding the 3 µm cut-off. Only 4±3% of the control cardiomyocytes (274 cells, 4 rats) could be considered as deficient, according to this parameter (>21% occurrence of long INT). Compared to control, in the hearts of STZ-NG and STZ-HG rats, the fractions of such deficient cardiomyocytes were statistically significantly higher: 48±13% (STZ-NG, 8 rats, 573 cells) and 76±8% (STZ-HG, 4 rats, 247 cells). Thus, structural changes in the T-system of the rat heart LV cardiomyocytes develop early during chronic hyperglycemia (overt diabetes) as well as during near-normoglycemic stages of diabetes (prediabetes). The relevance of these changes to the development of DCM in subjects with prediabetes remains to be studied.
- Добавил в систему: Бобков Данила Евгеньевич