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Simultaneous technetium‐99 MAG 3 , iodine‐131‐orthoiodohippurate and iodine‐125 iothalamate clearance and biodistribution after bolus injection in rats
Author(s) -
Casadevall G.,
Turull A.,
Piera C.,
Queralt J.
Publication year - 2000
Publication title -
biopharmaceutics and drug disposition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 58
eISSN - 1099-081X
pISSN - 0142-2782
DOI - 10.1002/1099-081x(200007)21:5<181::aid-bdd227>3.0.co;2-j
Subject(s) - ligature , renal function , biodistribution , kidney , iodine , bolus (digestion) , technetium , nuclear medicine , excretion , medicine , urology , clearance , renal physiology , scintigraphy , chemistry , biochemistry , organic chemistry , in vitro
A bolus injection multiple blood sampling method was developed for the simultaneous measurement of blood and plasma clearance of three radiopharmaceuticals in rats. Technetium‐99m mercaptoacetyltriglycine ([ 99m Tc]MAG 3 ) and iodine‐131‐orthoiodohippurate ([ 131 I]OIH) were used as makers of effective renal blood flow (ERBF), and iodine‐125 iothalamate ([ 125 I]IOT) was used as a marker of glomerular filtration rate (GFR). These methods can be easily performed in rats without arterial catheterization. Tissue biodistribution was studied in four groups of rats subjected to the following: group A, renal pedicle isolation (sham‐operated); group B, ligature of one kidney pedicle; group C, ligature of both renal pedicles; and group D, ligature of both kidney pedicles and the bile duct. Renal clearance of [ 99m Tc]MAG 3 was greater than [ 131 I]OIH and both agents were cleared faster than ([ 125 I]‐IOT). Either of the two markers of ERBF may be used in experimental studies, but it should be borne in mind that these are relative measurements of kidney performance. [ 99m Tc]MAG 3 and [ 125 I]‐IOT showed bile excretion in healthy rats, so they cannot completely fulfill the requirements for use as markers of ERBF. When renal function was impaired experimentally, [ 99m Tc]MAG 3 and [ 125 I]‐IOT were excreted in bile and [ 131 I]OIH was secreted in the intestine. Thus, while the markers of ERBF and GFR may be reliable under normal physiological conditions, they may give progressively more erroneous values as renal function deteriorates. Copyright © 2000 John Wiley & Sons, Ltd.