99mTc-low density lipoprotein: Intracellularly trapped radiotracer for noninvasive imaging of low density lipoprotein metabolism in vivo Academic Article Article uri icon


MeSH Major

  • Neuroendocrine Tumors
  • Radiopharmaceuticals
  • Tomography, Emission-Computed, Single-Photon


  • Low density lipoprotein (LDL) is the major transport protein for endogenous cholesterol in human plasma. LDL can be radiolabeled with 99mTc using sodium dithionite as a reducing agent. Biodistribution studies of 99mTc-LDL in normal rabbits confirm that 99mTc-LDL acts as an intracellularly "trapped ligand" similar to radioiodinated tyramine cellobiose-LDL (the previously validated trapped radioligand). In addition, studies performed in hypercholesterolemic rabbit models demonstrated the feasibility of imaging hepatic LDL-receptor concentration noninvasively. 99mTc-LDL imaging studies in a number of hypercholesterolemic and hypocholesterolemic patients have proven useful in understanding the abnormal uptake and metabolism of LDL. In patients with hypercholesterolemia (HC), 99mTc-LDL appears to be taken up well by the actively evolving atherosclerotic lesions and xanthomata that contained foam cells and macrophages. In patients with myeloproliferative disease and chronic hypocholesterolemia, 99mTc-LDL images showed intense accumulation of radioactivity in the spleen and bone marrow; this demonstrated extensive proliferation of the macrophage population suggesting that hypocholesterolemia in these patients may be due to increased uptake of LDL uptake by the macrophages. 99mTc-LDL is a powerful tool for the noninvasive exploration of a variety of disorders of lipoprotein metabolism in patients.

publication date

  • January 1990



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1016/S0001-2998(05)80177-1

PubMed ID

  • 2404342

Additional Document Info

start page

  • 68

end page

  • 79


  • 20


  • 1