Degradation of circulating thyroglobulin

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · Metab., Clin. Exp.; (United States)

DOI:https://doi.org/10.1016/0026-0495(85)90143-X· OSTI ID:6081115

Taura, M; Yamashita, S; Kubo, I; Izumi, M; Nagataki, S

In order to elucidate whether the derivatives of rat Tg in the peripheral circulation affect the results of kinetic studies of Tg, the present study was performed to investigate kinetics of rat Tg after separation of 19S Tg from its derivatives using gel-filtration. Radiolabeled Tg was obtained from thyroids of rats injected with SVI 24 hours before death, and subsequently purified by ammonium sulfate precipitation. The plasma samples obtained at varying time intervals after intravenous injection of SVI-rat Tg were fractionated on a Sephacryl S-300 column. As determined by sucrose density gradient, 99% of in vivo radiolabeled Tg was 19S. On gel-filtration, the injected labeled Tg and plasma samples obtained within two hours after injection showed a single peak in an identical area. A second peak in an area corresponding to a molecular weight of 60,000 to 70,000 appeared within six hours, and became as high as the first within 24 hours. In the second peak, 22.8% radioactivity was precipitated by anti-rat Tg antibody, and 14.4% of radioactivity of its TCA precipitate was not extracted by n-butanol. Thus, the second peak could affect the results of Tg kinetic studies which utilize TCA precipitation, n-butanol extraction or RIA procedures. The half life of rat Tg in the present study was calculated from the disappearance curves of radioactivity of 19S Tg separated from other radioactive substances.

• Research Organization: Nagasaki Univ., Japan
• OSTI ID: 6081115
• Journal Information: Metab., Clin. Exp.; (United States), Journal Name: Metab., Clin. Exp.; (United States) Vol. 10; ISSN METAA
• Country of Publication: United States
• Language: English

Related Subjects

560172* -- Radiation Effects-- Nuclide Kinetics & Toxicology-- Animals-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BETA DECAY RADIOISOTOPES
BIODEGRADATION
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
ELECTRON CAPTURE RADIOISOTOPES
GLOBULINS
HALF-LIFE
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
RADIONUCLIDE KINETICS
RATS
RODENTS
THYROGLOBULIN
VERTEBRATES