Rapid vascular escape of arterially injected 16alpha-radioiodo, 17beta-estradiol

Journal Article · Sat Mar 20 00:00:00 EST 1993 · International Journal of Radiation Oncology, Biology and Physics; (United States)

DOI:https://doi.org/10.1016/0360-3016(93)90208-D· OSTI ID:6722538

Scharl, A; Holt, J A ^[1]

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1. Univ. of Chicago, IL (United States)

The authors undertook this study because confirmation of a rapid vascular escape and slow release back into the circulatory system suggests that arterial injection of radiohalogenated steroid receptor ligands might provide an efficacious route of administration for imaging or treatment of receptor-rich malignant tumors in peripheral tissues. The authors injected radiolabeled 16alpha-iodo, 17beta-estradiol ([I]-E) into the femoral artery of swine in a solution that contained [[sup 125]I]-E in a known ratio to [[sup 99]Tc]-labeled red blood cells. Fractions of femoral venous blood were collected at short intervals during 10 min. They looked for changes in the ratio of the radiolabeles. [[sup 99m]Tc]-labeled red blood cells are known to remain in the vascular system for an hour or more. After passage of the injectate through the capillary bed of the swine leg, a dramatic decrease of the initial [sup 125]I:[sup 99m]Tc ratio to only 10% was observed in the femoral venous blood. This ratio increased gradually during the next 10 min to approximately 30% of that in the injectate, indicating that a significant portion (approximately 90%) of the [[sup 125]I]-E was initially trapped in the limb and then slowly re-entered the vascular system. To obtain visual confirmation of the rapid vascular escape of iodo-estrogen, they injected either an imageable form of [I]-E ([[sup 123]I]-E) or [[sup 99m]Tc]-labeled red blood cells into the dorsal aorta of superovulated rabbits, whose smaller size allowed whole-body imaging. The biodistributions of these radiopharmaceuticals were surveyed continuously by real-time planar gamma imaging. A large fraction of [I]-E escapes from the vascular system during the first pass through an organ or limb, without regard to the estrogen receptor content of the tissue. 28 refs., 3 figs., 1 tab.

• OSTI ID: 6722538
• Journal Information: International Journal of Radiation Oncology, Biology and Physics; (United States), Vol. 26:2; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ESTRADIOL
INJECTION
LABELLING
RADIOPHARMACEUTICALS
TISSUE DISTRIBUTION
BIOMEDICAL RADIOGRAPHY
NEOPLASMS
RADIOTHERAPY
DIAGNOSTIC TECHNIQUES
DISEASES
DISTRIBUTION
DRUGS
ESTRANES
ESTROGENS
HORMONES
HYDROXY COMPOUNDS
INTAKE
LABELLED COMPOUNDS
MEDICINE
NUCLEAR MEDICINE
ORGANIC COMPOUNDS
RADIOLOGY
STEROID HORMONES
STEROIDS
THERAPY
560160* - Radionuclide Effects
Kinetics
& Toxicology