Scintillation autoradiographic localization of 1,25-dihydroxyvitamin D/sub 3/ in chick intestine. [Tritium tracer techniques]

Journal Article · Thu Feb 01 00:00:00 EST 1979 · Endocrinology; (United States)

OSTI ID:6371721

Jones, P G; Haussler, M R

The intracellular binding site of 1,25-dihydroxyvitamin D/sub 3/ (1,25(OH)/sub 2/D/sub 3/) was determined via biochemical analysis of radioactive 1,25(OH)/sub 2/D/sub 3/ association with various chick tissues and then by direct autoradiography. When vitamin D-deficient chicks were injected intracardially with doses of tritiated 1,25(OH)/sub 2/D/sub 3/ and killed 2 h later, 2 to 3 times more radioactivity was found in the intestinal mucosa than was present in equal weights of pancreas, parathyroid, or liver tissue. Very little tritium was found in muscle tissue. The intestinally localized radioactivity was predominantly associated with the nuclear chromatin fraction, and binding of 1,25(OH)/sub 2/(/sup 3/H)D/sub 3/ to the nucleus was maximal 2 h after injection and at a dose of at least 0.52 nmol. Using this dose and time period, autoradiographic studies were done on duodenum and thoracic muscle of rachitic chicks injected with radioactive 1,25(OH)/sub 2/D/sub 3/ (11.2 Ci/mol). Thin sections of tissue were prepared for thaw and dry mount scintillation autoradiography as well as simple dip-coating autoradiography. After exposure for 4 to 6 months, a preferential concentration and retention of tritium-labeled 1,25(OH)/sub 2/D/sub 3/ was evident in the nuclei of intestinal villi and in the crypt of Lieberkuehn cells when each of the autoradiographic techniques was utilized. Quantitation of the labeled hormone confirms the significant nuclear accumulation in both villi and crypt cells. No such nuclear concentration of silver grains was observed in thoracic muscle cells, and the intestinal localization was abolished when a 100-fold excess of unlabeled 1,25(OH)/sub 2/D/sub 3/ was injected simultaneously with the radioactive hormone. It is concluded that 1,25(OH)/sub 2/D/sub 3/ is bound in a tissue-selective fashion to a high affinity, low capacity site within the nucleus of its intestinal target organ.

• Research Organization: Univ. of Arizona College of Medicine, Tucson
• OSTI ID: 6371721
• Journal Information: Endocrinology; (United States), Vol. 104:2
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CHOLECALCIFEROL
BIOLOGICAL LOCALIZATION
INTESTINES
SCINTISCANNING
LIVER
MUSCLES
PANCREAS
PARATHYROID GLANDS
TRITIUM
AUTORADIOGRAPHY
CHEMICAL ANALYSIS
CHICKENS
EXPERIMENTAL DATA
GRAPHS
ISOLATED VALUES
TRACER TECHNIQUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIRDS
BODY
COUNTING TECHNIQUES
DATA
DATA FORMS
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
ENDOCRINE GLANDS
FOWL
GASTROINTESTINAL TRACT
GLANDS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
VERTEBRATES
VITAMIN D
VITAMINS
YEARS LIVING RADIOISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics