Ultrastructural and Functional Changes in Liver Mitochondria in a Rat Model of Type I Diabetes Mellitus

—The characteristics of the ultrastructure and functioning of mitochondria in the liver of Sprague Dawley rats in the experimental model of type I diabetes mellitus have been investigated. It has been found that diabetes mellitus induced in response to streptozotocin administration at a dose of 75 mg/kg body weight was accompanied by disturbances in the structural organization of mitochondrial cristae and a decrease in the size of the organelles compared to the control. It has been also demonstrated that in type I diabetes the respiratory rates of liver mitochondria in metabolic states 2, 3, and 4 increase. This may be associated with an increase in the total content of fatty acids in liver mitochondria of diabetic rats. At the same time, streptozotocin-induced diabetes mellitus in rats did not affect the indices of oxidative phosphorylation efficiency (ADP/O, respiratory control ratio, and phosphorylation time) in liver mitochondria.