Biologic activity of the iodoestrogens and their use in breast cancer

Journal Article · Thu Jan 01 00:00:00 EST 1981 · Adv. Exp. Med. Biol.; (United States)

OSTI ID:6783270

Longcope, C; Arunachalam, T; Rafkind, I; Caspi, E

Several iodinated estrogens, 6-iodoestra-1,3,5(10), 6-tetraene-3, 17 beta-diol (4) 16 beta-iodo-estradiol (3) were shown to displace /sup 3/H-estradiol (1b) from the uterine cytosol receptor by a competitive type of inhibition. The three compounds translocated the cytosol receptor to the nucleus in vitro and increased mouse uterine weight in vivo. In all tests the relative activities were 16 alpha-(2a) greater than 16 beta-(3a) greater than 6-(4a). When the compounds were made with (/sup 125/I) the 16 alpha-(/sup 125/I)-iodoestradiol (2b) bound with high affinity, Kd . 0.4 x 10(-10), to the 8S cytosol receptor. No high affinity binding could be demonstrated for the 6-(/sup 125/I)-iodoestratetraene (4b). In in vivo experiments following the administration of 16 alpha-(/sup 125/I)-iodoestradiol (2b) to rats, high levels of radioactivity were found in the uterus, liver and thyroid but only in the liver and thyroid following administration of 6-(/sup 125/I)-iodoestratetraene (4b). After administration of (2b) to rats with DMBA-induced mammary tumors, no tumor concentration of radioactivity could be detected by imaging. When (4b) was administered similarly, radioactivity could be detected in some of the tumors by imaging. The radioactivity was associated with non-specific 4S proteins.

• Research Organization: Worcester Foundation for Experimental Biology, Shrewsbury, MA
• OSTI ID: 6783270
• Journal Information: Adv. Exp. Med. Biol.; (United States), Vol. 138
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
IODINE 125
ISOTOPE APPLICATIONS
MAMMARY GLANDS
SCINTISCANNING
NEOPLASMS
DIAGNOSIS
TRITIUM COMPOUNDS
BIOCHEMISTRY
BIOLOGICAL LOCALIZATION
ESTROGENS
LABELLED COMPOUNDS
LIVER
RATS
RECEPTORS
THYROID
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ANIMALS
BETA DECAY RADIOISOTOPES
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CHEMISTRY
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DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
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ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE GLANDS
FEMALE GENITALS
GLANDS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RODENTS
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