title: A microassay for mammalian renal 25-hydroxyvitamin D3-1-hydroxylase applicable to man.
abstract: A micro determination of the renal 25-hydroxyvitamin D3-1-hydroxylase activity was developed that uses as little as 1 mg of rat kidney tissue. The method was applied to the remaining portions of needle kidney biopsy specimens taken for diagnostic purposes from children who had asymptomatic proteinuria and/or hematuria (more than 1-year duration) but were otherwise normal in calcium metabolism and renal function. The 25-hydroxyvitamin D3-1-hydroxylase levels of these children were found to be 66 1,25-dihydroxyvitamin D3 per milligram of tissue per 20 min for an 11-year-old male, 117 pg for a 9-year-old male, and 89 pg for a 10-year-old female.
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D000818:Animals; D002648:Child; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006417:Hematuria / Q000201:enzymology; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D008297:Male; D008832:Microchemistry; D011507:Proteinuria / Q000201:enzymology; D051381:Rats; D013056:Spectrophotometry, Ultraviolet; D013250:Steroid Hydroxylases / Q000032:analysis*
chemical_list: D013250:Steroid Hydroxylases; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase