[The ROS-generating and antioxidant systems in the liver of rats treated with prednisolone and vitamin D3].

The mechanisms of glucocorticoid-induced disturbances of liver function is currently not fully clarified. Vitamin D3 was previously shown to play an important role in the regulation of impaired oxidative metabolism and detoxification function of the liver associated with the effects of hepatotoxic compounds. The study was undertaken to define the intensity of oxidative metabolism in the rat liver and survival of hepatocytes after prolonged prednisolone administration and to assess whether vitamin D3 is capable to counter glucocorticoid-induced changes.

[Immunomodulatory effects of vitamin D3 and bisphosphonates in nutritional osteoporosis in rats].

The aim of this study was to determine the effectiveness of separate and combined administration of vitamin D3 and different forms of bisphosphonate (disodium salt of methylenbisphosphonic acid dihydrate and alendronate) on the function of immune cells in rats with nutritional osteoporosis. It was shown that D-hypovitaminosis leads to reduced 25OHD3, which is a biomarker for vitamin D3 and disturbances of metabolic processes in bone tissue that correlated with osteoporosis manifestation. Immunologic disorders related to nutritional osteoporosis were accompanied by the decrease in phagocytic activity of granulocytes and impaired ability to produce bactericidal oxidants.

[Features of cholecalciferol hydroxylation in the liver of rats in conditions of D-hypervitaminosis and activity of alpha-tocopherol].

It is shown, that hepatocytes contain two (microsomal and mitochondrial) vitamin D3 25-hydroxylase enzymes, which differ as to their activity and function with maximal activity at different concentrations to substrate, namely at 15 microM and 100 microM of vitamin D3, accordingly. Activity of vitamin D3 25-hydroxylase enzymes of hepatocytes is regulated by cholecalciferol and alpha-tocopherol. The general and microsomal vitamin D3 25-hydroxylase enzymes activity of hepatocytes is lowered, but mitochondrial isoform is increased under D-hypervitaminosis conditions.

[Role of vitamin E in regulation of cholecalciferol hydroxylation in hypovitaminosis D and hypervitaminosis D].

It is established, that dose-dependent influence of vitamin E on vitamin D3 metabolism, is conditioned by degree of cholecalciferol sufficiency. Under a condition of D-hypovitaminosis, contents of 25OHD3 in blood serum is 2-fold reduced and vitamin D3 25-hydroxylase enzymes activity increased in rat hepatocytes. Vitamin E (0.

[Content and transportation of Ca(2+) to hepatocytes and lipid content of liver cell membrane structure in experimental diabetes in the rat].

It is proved that at experimental diabetes the calcium content in hepatocytes is disturbed. This disorder is mostly shown in increase of calcium content in hepatocytes and in decrease of accumulation of these ions in mitochondrias. One of the possible reasons of changes at this pathology is the change of lipid content of hepatocytes, mitochondrias and microsomes.