Pathological Changes in Liver Mitochondria of Rats with Experimentally Induced Hyperthyroidism and Their Correction with Uridine.

The aim of the study was to examine how the administration of uridine influences the mitochondrial function in hepatocytes in a rat model of hyperthyroidism (HT) induced by thyroxine treatment. Excess thyroid hormones (TH) increased the mitochondrial oxygen consumption, enhanced biogenesis, and altered the expression of proteins regulating the mitochondrial fusion and fission. Hyperthyroid rats had a mixed population of mitochondria, including swollen and damaged organelles. Although uridine did not affect the level of serum TH, it restored the normal body weight. The administration of uridine used for therapeutic purposes improved the main parameters of respiration and oxidative phosphorylation, prevented destructive changes in the morphology of liver mitochondria, and influenced the biogenesis and dynamics of these organelles. Overall, the results obtained indicate that uridine has a protective effect against functional and some structural destructions in rat liver mitochondria induced by HT.