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

Journal Article · Tue Jan 01 00:00:00 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), Vol. 32:1; ISSN 0022-2275
• Country of Publication: United States
• Language: English

Related Subjects

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