Adrenal imaging with technetium-99m-labelled low density lipoproteins
Plasma low density lipoproteins (LDL) are a major source of cholesterol for adrenal cortical steroid hormones synthesis. To test whether LDL labelled with Tc-99m could be used to assess adrenal cortical function, the authors prepared Tc-99m-LDL by dithionite reduction of Tc0/sub 4//sup -/ in the presence of LDL. About 80% of the Tc-LDL bonds were covalent. Purified Tc-99m-LDL was injected intravenously into 16 rabbits (4 t 8mCi/rabbit). External imaging was carried out 16 to 18 hrs later, at which time the adrenals were visualized clearly; the animals were sacrificed, the organs dissected out, weighed, and counted. The biodistribution demonstrated that 0.8l +- 0.19% of the injected radioactivity was taken up per gm of whole adrenal gland. This compared with an uptake of 0.19 +- 0.02% per gm by liver, 0.22 +- 0.04% per gm by spleen, and 0.11 +- 0.02% per gm by kidney. To verify that they were indeed imaging the adrenals, additional rabbits were tested with dexamethasone. First they were injected with Tc-99m-LDL; 28 hrs later the adrenals were again well visualized. Then the rabbits were given dexamethasone for 5 days to suppress adrenal cortical function. The adequacy of suppression was monitored by serum cortisol measurements. When Tc-99m-LDL was injected again, the adrenals could not be seen 18 hrs later. Counts of the adrenals from the suppressed rabbits were at background levels. These data indicate that Tc-99m-LDL is a useful radiopharmaceutical for evaluating adrenal cortical function.
- Research Organization:
- New England Deaconess Hospital, Boston, MA
- OSTI ID:
- 7088935
- Report Number(s):
- CONF-840619-
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
- Country of Publication:
- United States
- Language:
- English
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ADRENAL GLANDS
RADIOISOTOPE SCANNING
LIPOPROTEINS
DIAGNOSTIC USES
LABELLING
RABBITS
TECHNETIUM 99
ADRENAL HORMONES
DENSITY
IMAGE PROCESSING
IMAGES
INTRAVENOUS INJECTION
UPTAKE
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
COUNTING TECHNIQUES
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HORMONES
HOURS LIVING RADIOISOTOPES
INJECTION
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INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIPIDS
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHYSICAL PROPERTIES
PROCESSING
PROTEINS
RADIOISOTOPES
STEROID HORMONES
TECHNETIUM ISOTOPES
USES
VERTEBRATES
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550601* - Medicine- Unsealed Radionuclides in Diagnostics