title: Changes in 25-hydroxyvitamin D3 alpha- and 24-hydroxylase activities of kidney cells isolated from rats with either unilateral kidney damage or acute renal insufficiency.
abstract: 25-Hydroxyvitamin D3 1 alpha- and 24-hydroxylase, NADPH-cytochrome c reductase, heme oxygenase, and ATPase activities were studied in viable kidney cells isolated from rats submitted to unilateral kidney damage (cortical electrocoagulation) and during the development of acute renal failure subsequent to excision of the contralateral undamaged kidney. Measurements of blood pH, plasma total and ionized calcium, phosphorus, creatinine, kidney histology, and phosphorus nuclear magnetic resonance spectroscopy determinations of phosphorus-containing compounds in kidney tissue were also performed. Seventy-two hours after unilateral kidney damage, no significant changes were observed in blood pH or in the plasma parameters studied. During this period, a significant increase in the activity of the 25-hydroxyvitamin D3 hydroxylases could be demonstrated in the cells of the contralateral undamaged kidney. A similar pattern of compensatory rise in the activity of the other enzymes studied was not detected. However, in the damaged kidney viable cells, the hydroxylase activities remained unchanged relative to those in sham-operated controls, despite a 5-fold increase in the inorganic phosphate content and a marked decrease in the organophosphorus and ATP content of this tissue. During the development of acute renal failure, a significant decrease in the activity of the hydroxylases occurred only when the rise in plasma creatinine concentration suggested severe renal insufficiency.
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000378:metabolism*; D058186:Acute Kidney Injury / Q000201:enzymology*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D003577:Cytochrome P-450 Enzyme System; D007839:Functional Laterality; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D007668:Kidney / Q000201:enzymology* / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013250:Steroid Hydroxylases / Q000378:metabolism*; D065668:Vitamin D3 24-Hydroxylase
chemical_list: D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D006419:Heme Oxygenase (Decyclizing); D065668:Vitamin D3 24-Hydroxylase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D009251:NADPH-Ferrihemoprotein Reductase; D000251:Adenosine Triphosphatases