Adrenal imaging with technetium-99m-labelled low density lipoproteins

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:7088935

Isaacsohn, J L; Lees, A M; Lees, R S; Kovach, M B; Strauss, H W

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-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ADRENAL GLANDS
ADRENAL HORMONES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
COUNTING TECHNIQUES
DENSITY
DIAGNOSTIC USES
ENDOCRINE GLANDS
GLANDS
HORMONES
HOURS LIVING RADIOISOTOPES
IMAGE PROCESSING
IMAGES
INJECTION
INTAKE
INTERMEDIATE MASS NUCLEI
INTRAVENOUS INJECTION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLING
LIPIDS
LIPOPROTEINS
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHYSICAL PROPERTIES
PROCESSING
PROTEINS
RABBITS
RADIOISOTOPE SCANNING
RADIOISOTOPES
STEROID HORMONES
TECHNETIUM 99
TECHNETIUM ISOTOPES
UPTAKE
USES
VERTEBRATES
YEARS LIVING RADIOISOTOPES