THE PURITY OF RADIOIODIDE-I$sup 131$ ASSESSED BY IN VIVO AND IN VITRO METHODS

Journal Article · Sat May 26 04:00:00 EDT 1962 · Canadian Medical Association Journal (Canada)

OSTI ID:4770800

Fawcett, D M; Olde, G L; McLeod, L E

Anomalous results from in vitro studies of thyroid metabolism have led to investigation of the purity of commercial samples of I/sup 131/. Analysis of 30 I/sup 131/ preparations by paper chromatography showed that samples supplied without cysteine preservative contain appreciable quantities of non-iodide radioactivity. From 41 to 94% of the radioactivity was non-iodide. Extraneous radioactivity was essentially absent from I/sup 131/ supplied with cysteine. It was converted to iodide-I/sup 131/ by 10/sup -3/ M cysteine or iodide but not by incubation at pH 2. The average thyroid uptake of I/sup 131/ containing extraneous radioactivity was significantly lower than the uptake of I/sup 131/ free from non-iodide impurity in 16 human subjects measured under controlled conditions and in a random group of 669 patients. Incubation of samples of I/sup 131/ containing non-iodide radioactivity with tyrosine and CuCl/sub 2/ resulted in nonenzymatic formation of ence of thyroid homogenate. Enzymatic formation of monoiodoonly when I/sup 131/ free from extraneous activity was used. (H.H.D.)

• Research Organization: Alberto Hospital, Edmonton, Can.
• NSA Number: NSA-16-032665
• OSTI ID: 4770800
• Journal Information: Canadian Medical Association Journal (Canada), Journal Name: Canadian Medical Association Journal (Canada) Vol. Vol: 86; ISSN CMAJA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDITY
AMINO ACIDS
BIOCHEMISTRY
BIOLOGY AND MEDICINE
CHROMATOGRAPHY
COPPER CHLORIDES
CYSTEINE
ENZYMES
HORMONES
IMPURITIES
IODIDES
IODINE 131
LABELLED COMPOUNDS
MAN
MEASURED VALUES
METABOLISM
QUALITATIVE ANALYSIS
RADIOACTIVITY
SAMPLING
THYROID
TYROSINE