In chronic renal disease certain changes occur in the levels and physicochemical state of calcium, magnesium, and inorganic phosphate. Variation in concentrations of phosphate and calcium are believed to underly certain abnormalities in parathyroid and bone metabolism which occur in uremia.1 In this report, observations made in our laboratories at the Los Angeles Veterans Administration Center and Cedars-Sinai Medical Center over the past several years will be reviewed.
Calcium and magnesium levels were determined with either the atomic absorption spectrophotometer or the oxygen-acetylene flame photometer2 except where noted otherwise. Ultrafiltrates of sera were prepared anaerobically in Lavietes chambers at room temperature, and ionized calcium levels were determined in anaerobic ultrafiltrates by a micromodification of the 2-wavelength murexide method of Ettori and Scoggan.3 Complexed calcium was determined by the difference between diffusible and ionized calcium. Creatinine, phosphate, and sodium levels were determined with standard methods previously reported from
Coburn JW, Popovtzer MM, Massry SG, Kleeman CR. The Physicochemical State and Renal Handling of Divalent Ions in Chronic Renal Failure. Arch Intern Med. 1969;124(3):302–311. doi:10.1001/archinte.1969.00300190042007