The effect of dietary protein on the biological activity of cholecalciferol and its metabolites in the rachitic rat.
Rats maintained on low-protein rachitogenic diets show increased intestinal calcium transport, serum inorganic phosphate and increased endochondral calcification responses to calciferol, 25-hydroxycholecalciferol (25-OH-CC) and 1,25-dihydroxycholecalciferol (1,25-(OH)2CC). Because enhanced responses are observed with 1,25-dihydroxycholecalciferol as well as its precursors, it is unlikely that the effect of dietary protein is mediated by a change in the calciferol-25-hydroxylase and the 25-hydroxycholecalciferol-1 alpha-hydroxylase. Instead, it appears that either metabolism of 1,25-dihydroxycholecalciferol or its activity in the target organs is affected.
D000818:Animals; D001835:Body Weight; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002762:Cholecalciferol / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D004100:Dihydroxycholecalciferols / Q000494:pharmacology; D006887:Hydroxycholecalciferols / Q000494:pharmacology; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D051381:Rats; D012279:Rickets / Q000378:metabolism*
D004044:Dietary Proteins; D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D002762:Cholecalciferol; D002118:Calcium