Effect of dietary phosphorus levels on porcine renal 25-hydroxyvitamin D-1 alpha- and 24R-hydroxylase activities and plasma 1,25-dihydroxyvitamin D3 concentration.
Results of studies on the effect of dietary P deprivation on pig renal 1 alpha- and 24-hydroxylase activities and on concentrations of plasma alkaline phosphatase, Ca, P and vitamin D metabolites are presented. Renal 1 alpha-hydroxylase activity was increased six- to eightfold and plasma 1,25-dihydroxyvitamin D3 concentration increased two- to threefold in pigs fed a low P diet (.085% P) compared with pigs fed a control diet (.6% P). In contrast, renal 24-hydroxylase activity and plasma 25-hydroxyvitamin D concentration did not differ between diet groups. Plasma alkaline phosphatase activity was two to four times higher in pigs fed the low P diet compared with pigs fed the control diet. The rate of gain by pigs fed the low P diet was less than pigs fed the control diet. The low P diet was associated with a prolonged elevation of renal 1 alpha-hydroxylase activity in spite of the presence of a pronounced hypercalcemia.
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001835:Body Weight; D002117:Calcitriol / Q000097:blood*; D002118:Calcium / Q000097:blood; D003577:Cytochrome P-450 Enzyme System; D005260:Female; D005527:Food, Fortified; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D010710:Phosphates / Q000008:administration & dosage; D010758:Phosphorus / Q000097:blood / Q000494:pharmacology*; D013250:Steroid Hydroxylases / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*; D065668:Vitamin D3 24-Hydroxylase
D010710:Phosphates; D010758:Phosphorus; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D065668:Vitamin D3 24-Hydroxylase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D000469:Alkaline Phosphatase; D002117:Calcitriol; C018279:sodium phosphate; D002118:Calcium