/sup 125/I iothalamate an ideal marker for glomerular filtration
The triiodinated angiographic contrast medium, iothalamate (usually labelled /sup 125/I), has been used extensively as a marker for glomerular filtration. The authors have studied the renal handling of /sup 125/I iothalamate (IOT) in vivo and in vitro in several species. In renal cortical slices from chicken, rabbit, rat, and monkey, the tissue-to-medium ratio of IOT was twice that of /sup 51/Cr-EDTA (EDTA) at 37 degrees C; a difference that was abolished at 0 degree C and markedly reduced by added o-iodohippurate or iodipamide. In five chickens the steady-state renal clearance of IOT (CIOT) was twice that of EDTA (CEDTA) or /sup 3/H inulin (C1); a difference that was abolished by administration of 100 mg/kg/hr of novobiocin, an organic anion transport inhibitor. CEDTA was similar to C1 before as well as after transport inhibition. Utilizing the Sperber technique the mean apparent tubular excretion fraction (ATEF) of IOT was 8%, while that of EDTA was 1%. After novobiocin coinfusion (new steady-state) ATEFIOT was significantly reduced and not different from that of EDTA (-1%). In the same animals the total urinary recovery of IOT was 84 and 57% before and after novobiocin, respectively, while corresponding values for EDTA was unchanged by the inhibitor. In seven rats the renal extraction of IOT was reduced from 29 to 17% by coinfusion of probenecid (5 mg/kg/hr). Corresponding extractions were 82 to 34% and 22% (unchanged) for PAH and EDTA, respectively.
- Research Organization:
- Univ. Hospital, Uppsala, Sweden
- OSTI ID:
- 5644158
- Journal Information:
- Kidney Int.; (United States), Vol. 27:1
- Country of Publication:
- United States
- Language:
- English
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CONTRAST MEDIA
RENAL CLEARANCE
KIDNEYS
DYNAMIC FUNCTION STUDIES
ANTIBIOTICS
CHICKENS
CHROMIUM 51
EDTA
GLOMERULI
IN VITRO
IN VIVO
IODINE COMPOUNDS
MONKEYS
RABBITS
RATS
TEMPERATURE DEPENDENCE
TRITIUM COMPOUNDS
AMINO ACIDS
ANIMALS
ANTI-INFECTIVE AGENTS
BETA DECAY RADIOISOTOPES
BIRDS
BODY
CARBOXYLIC ACIDS
CHELATING AGENTS
CHROMIUM ISOTOPES
CLEARANCE
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
EXCRETION
FOWL
HALOGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PRIMATES
RADIOISOTOPES
RODENTS
VERTEBRATES
550602* - Medicine- External Radiation in Diagnostics- (1980-)