Partial characterization of low density lipoprotein preparations isolated from fresh and frozen plasma after radiolabeling by seven different methods

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Journal of Lipid Research; (USA)

OSTI ID:5683429

Atsma, D E; Kempen, H J; Nieuwenhuizen, W; van 't Hooft, F M; Pauwels, E K ^[1]

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1. Gaubius Institute TNO, Leiden (Netherlands)

Four {sup 99m}Tc and three {sup 123}I labeling methods were evaluated for their suitability to label low density lipoproteins (LDL) for the purpose of scintigraphic biodistribution studies. For {sup 99m}Tc these methods were: direct incorporation in LDL of {sup 99m}TcO4- using sodium dithionite (dithionite method); a method using first N,N-dimethylformamide to prepare a {sup 99m}Tc-complex reacting with LDL in a subsequent step (DMF method); a technique in which {sup 99m}TcO4- is first coupled to a diamide dithiolate derivative of pentanoic acid by reduction with dithionite, followed by coupling of this ligand to LDL (N2S2 method); and a method using sodium borohydride and stannous chloride as reducing agents (borohydride method). The iodination techniques were based on oxidation of I(-)----I+, using iodine monochloride (ICl method), 1,3,4,6-tetrachloro-3,6-diphenylglycoluril (Iodogen method), and N-bromosuccinimide (NBS method) as oxidants. We studied labeling yields, modification of LDL caused by the labeling procedures using agarose-gel electrophoresis, and radiochemical stability of the labeled LDL complex upon incubation in plasma at 37 degrees C for 15 h. We used Sepharose CL6B chromatography to separate LDL from other plasma proteins. We also examined whether LDL isolated from frozen plasma (Pool-LDL) gave results similar to LDL obtained from freshly prepared plasma (Fresh-LDL). Pool-LDL radiolabeled by the dithionite, DMF, NBS, and Iodogen methods lost its label upon incubation with plasma. This also happened with Fresh-LDL when the DMF, NBS and Iodogen methods were used. Upon agarose-gel electrophoresis, no modification of LDL was observed with all methods when the radionuclide/LDL ratio was kept low.

• OSTI ID: 5683429
• Journal Information: Journal of Lipid Research; (USA), Journal Name: Journal of Lipid Research; (USA) Vol. 32:1; ISSN JLPRA; ISSN 0022-2275
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL PREPARATION
CHROMATOGRAPHY
COUNTING TECHNIQUES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE ISOTOPES
ISOMERIC NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LABELLING
LIPIDS
LIPOPROTEINS
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RABBITS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RADIOPHARMACEUTICALS
SCINTISCANNING
SEPARATION PROCESSES
SYNTHESIS
TECHNETIUM 99
TECHNETIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES