99mTechnetium-labeled low density lipoprotein: Receptor recognition and intracellular sequestration of radiolabel

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

OSTI ID:5802275

Lees, A M; Lees, R S ^[1]

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1. New England Deaconess Hospital, Boston, MA (USA)

{sup 99M}Technetium-labeled low density lipoprotein ({sup 99M}Tc-labeled LDL) was developed to detect atherosclerosis by external imaging with the gamma scintillation camera. The present study examined high affinity LDL receptor recognition and intracellular sequestration of {sup 99M}Tc-labeled LDL by fibroblasts. There were no significant differences between {sup 99M}Tc-labeled LDL and {sup 125}I-labeled LDL in binding parameters or percent inhibition of accumulation, which indicated that {sup 99M}Tc labeling did not alter receptor recognition of LDL. At 4 degrees C the Kd (+SE) for {sup 99M}Tc-labeled LDL and {sup 125}I-labeled LDL, respectively, was 1.52 +/- 0.24 and 1.45 +/- 0.14 micrograms/ml; Bmax (+/- SE) was 5.45 +/- 0.48 and 4.89 +/- 0.25 ng/well, respectively. Binding was saturated at about 2 micrograms/ml. The complete linearity of {sup 99M}Tc-labeled LDL accumulation from 0-6 h and the positive slope from 6-24 h indicated that radiolabel that entered cells as {sup 99M}Tc-labeled LDL was sequestered; pulse-chase experiments, which measured residual cell-associated radioactivity out to 24 h, also showed that radiolabel was trapped. Because radiolabel sequestration was essentially complete, and because {sup 99M}Tc-labeled LDL was recognized by the LDL receptor equally as well as {sup 125}I-labeled LDL, it should be useful not only for imaging atherosclerosis, but also for quantitatively determining sites of utilization and degradation of LDL.

• OSTI ID: 5802275
• 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
ANIMAL CELLS
ANIMALS
ARTERIOSCLEROSIS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CAMERAS
CARDIOVASCULAR DISEASES
CELL CONSTITUENTS
CONNECTIVE TISSUE CELLS
CYTOPLASM
DAYS LIVING RADIOISOTOPES
DIAGNOSIS
DISEASES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
FIBROBLASTS
GAMMA CAMERAS
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOMERIC NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIPIDS
LIPOPROTEINS
MAMMALS
MAN
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PRIMATES
PROTEINS
RADIOISOTOPES
RADIOPHARMACEUTICALS
REACTION KINETICS
RECEPTORS
SOMATIC CELLS
TECHNETIUM 99
TECHNETIUM ISOTOPES
VASCULAR DISEASES
VERTEBRATES
YEARS LIVING RADIOISOTOPES