title: [Comparative study of the effects of alpha-25-dihydroxycholecalciferol and 24, 25-dihydroxycholecalciferol on calcium-phosphorus metabolism and on bone tissue in experimental kidney insufficiency in rats].
abstract: Experimental chronic kidney insufficiency (CKI; within 2-6 months) in rats, kept on a diet containing 0.6% Ca2+ and 0.6% P was accompanied by distinct azotemia, hyperphosphatemia, by a decrease in specific weight, in content of Ca2+, P and hydroxyproline in diaphyses as well as by a decrease in epiphyseal Ca2+. Daily administration of 0.025 micrograms of 1 alpha, 25-dihydroxy-cholecalciferol (1,25 (OH)2D3) into the animals did not normalize any of the patterns studied. At the same time, 1,25 (OH)2D3 increased the rate of hypercalciemia and demineralization of epiphyses, causing a slight hypercalciemia and increasing distinctly calcinosis of aorta as well as of the remaining part of the kidney. After daily administration of 24, 25-dihydroxycholecalciferol (24, 25 (OH)2D3) at a dose of 0.25 micrograms most of the patterns studied were normalized; specific weight, content of Ca2+ and P were increased in diaphyses simultaneously with a decrease in blood phosphorus concentration and in the level of azotemia. 24, 25 (OH)2D3 increased also the collagen content in diaphyses and epiphyses. The higher dose of 24, 25 (OH)2D3 (1.25 micrograms) did not exhibit higher effectivity. No one of the 24, 25 (OH)2D3 doses used did cause hypercalciemia and calcinosis. Combination of 0.025 micrograms 1,25 (OH)2D3 with 1.25 micrograms of 24, 25 (OH)2D3 decreased slightly the hypercalciemic, hyperphosphatemic and calcinosis inducing effects of 1,25 (OH)2D3 preventing completely the osteoporotic alterations in diaphyses but increasing the epiphysis demineralization; these results indicate that the doses of these metabolites must be decreased if their combination is required. The data obtained suggest that 24, 25 (OH)2D3 is a more effective and safe drug in correction of Ca2+-P metabolism impairments as well as of bone destruction under kidney insufficiency conditions as compared with 1,25 (OH)2D3.
mesh_terms: D015650:24,25-Dihydroxyvitamin D 3; D000818:Animals; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D002114:Calcinosis / Q000209:etiology / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D004100:Dihydroxycholecalciferols / Q000494:pharmacology*; D004195:Disease Models, Animal; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008297:Male; D010710:Phosphates / Q000378:metabolism*; D051381:Rats
chemical_list: D004100:Dihydroxycholecalciferols; D010710:Phosphates; D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol; D002118:Calcium
vernacular_title: Sravnitel'noe izuchenie vliianiia lal'fa, 25-dioksikholekal'tsiferola i 24, 25-dioksikholekal'tsiferola na fosforno-kal'tsievyĭ obmen i kostnuiu tkan' pri éksperimental'noĭ pochechnoĭ nedostatochnosti u krys.