[Effect of 1 alpha-hydroxycholecalciferol and of a varying phosphorus requirement on mineral metabolism in chronic renal insufficiency].

Experimental chronic kidney insufficiency caused in rats the impairments of phosphoerus-calcium turnover (hyperphosphatemia and hypocalcemia), osteoporotic alterations in bones (decreas in specific gravity, in content of Ca, P and hydroxyproline) as well as calcinosis of internal tissues, particularly in the impaired kidney tissue. Decrease in phosphorus content of food down to 0.3% inhibited distinctly the development of these impairments and modulated their severity, lowering mortality of the animals with chronic kidney insufficienty. Administration of physiologic doses (0.025 mg) of 1 alpha-hydroxy vitamin D3/(1 alpha OHD3) which is a synthetic analogue of 1,25-dihydroxycholecalciferol (hormonal form of vitamin D synthesized in kidney) into rats with chronic kidney insufficiency (with limited content of phosphorus in the food) did not exhibit any additional curative effect on the patterns of bone metabolism studied; in this case calcinosis was slightly increased and mortality of the animals also increased. After administration of 1 alpha OHD3 into rats with chronic kidney insufficiency, maintained on food containing 1.2% of phosphorus, impairments in phosphorus-calcium turnover were distinctly increased. Osteoporosis and calcinosis were elevated in the impared kidney; this led to death of all the animals within first 2 months of the experiments.