title: Parathyroid hormone stimulates mammalian renal 25-hydroxyvitamin D3-1 alpha-hydroxylase in vitro.
abstract: We have shown that parathyroid hormone (PTH) stimulates 25-hydroxyvitamin D2-1 alpha-hydroxylase activity in mitochondrial preparations of guinea pig kidney in vitro.1,25-[3H]dihydroxyvitamin D3 produced from 25-[3H]hydroxyvitamin D3 was identified by both normal phase and reversed-phase high pressure liquid chromatography. Enzyme stimulation by PTH was dose-dependent, peaked after 15 minutes of incubation with hormone and was maximal at concentrations of approximately 10(-10) M PTH-(1-84) and PTH-(1-34). This guinea pig renal model therefore permits direct examination of hormonal regulation of the mammalian enzyme in vitro.
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004789:Enzyme Activation; D006168:Guinea Pigs; D007672:Kidney Cortex / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D010281:Parathyroid Hormone / Q000494:pharmacology*; D013250:Steroid Hydroxylases / Q000378:metabolism*
chemical_list: D010281:Parathyroid Hormone; D013250:Steroid Hydroxylases; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase