The Measurement of Glomerular Filtration Rate and Effective Renal Plasma Flow in Man by Iothalamate 125I and Iodopyracet 131I
In 21 patients, 90 simultaneous renal clearances of inulin and sodium iothalamate 125I, and para-amino-hippuric acid (PAH) and iodopyracet 131I were determined by a constant infusion technique. The activities of iothalamate 125I and iodopyracet 131I were determined simultaneously in a dual-channel scintillation counter. The concentrations of inulin and PAH were determined by standard chemical techniques. The ratio of iothalamate 125I to inulin clearance ranged from 0.93 to 1.09 with a mean of 1.00. The ratio of iodopyracet 131I to PAH clearance varied from 0.86 to 1.04 with a mean of 0.96. The chemical determination of PAH and inulin required approximately 8 hours of technician time as compared with 30 minutes by the radioactive technique. The determination of the renal clearances of iothalamate 125I and iodopyracet 131I is an accurate and time-saving technique for the measurement of glomerular filtration rate and effective renal plasma flow.
- © 1967 American Heart Association, Inc.