Distribution of the muscarinic acetylcholine receptor antagonists, quinuclidinyl benzilate and quinuclidinyl benzilate methiodide (both tritiated), in rat, guinea pig, and rabbit
- 1. George Washington Univ. Medical Center, Washington, DC
Description
The distribution of [3H]quinuclidinyl benzilate and its methiodide salt was determined in rat, guinea pig, and rabbit. Accumulation in the myocardium of up to 2% of the injected dose per gram of tissue was obtained with both compounds, providing heart-to-blood ratios of approx. 30 and heart-to-lung ratios of approx. 4. The accumulation in the heart was blocked (89%) by preinjection of atropine. The distribution of tritium in rabbit heart corresponds to the muscarinic receptor densities determined in vitro. Calculation of the theoretical maximum for the bound-to-free ratio, based on in-vitro equilibrium binding isotherms, resulted in ratios in reasonable agreement with the experimental results. Because of the high accumulation in the heart with low serum concentration, we conclude that the methiodide salt of quinuclidinyl benzilate represents an ideal parent structure for the design of a receptor-binding gamma-emitting radiopharmaceutical for imaging of the myocardium
Additional details
Publishing Information
- Journal Title
- J. Nucl. Med.
- Journal Volume
- 20
- Journal Issue
- 8
- Series
- J. Nucl. Med.
- Journal Page Range
- 865-870
- ISSN
- 0022-3123
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 11505151
- Subject category
- S63: RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS; S62: RADIOLOGY AND NUCLEAR MEDICINE;
- Resource subtype / Literary indicator
- Numerical Data
- Descriptors DEI
- AROMATICS; BIOLOGICAL LOCALIZATION; BLOOD SERUM; DISTRIBUTION; EXPERIMENTAL DATA; GUINEA PIGS; IODIDES; ISOLATED VALUES; LUNGS; MYOCARDIUM; ORGANIC NITROGEN COMPOUNDS; RABBITS; RADIONUCLIDE KINETICS; RADIOPHARMACEUTICALS; RATS; RECEPTORS; SCINTISCANNING; TISSUES; TRITIUM COMPOUNDS
- Descriptors DEC
- ANIMALS; BODY; CARDIOVASCULAR SYSTEM; COUNTING TECHNIQUES; DATA; DATA FORMS; DIAGNOSTIC TECHNIQUES; DRUGS; HALIDES; HALOGEN COMPOUNDS; HEART; HYDROGEN COMPOUNDS; INFORMATION; IODINE COMPOUNDS; KINETICS; LABELLED COMPOUNDS; MAMMALS; MEDICINE; MUSCLES; NUCLEAR MEDICINE; NUMERICAL DATA; ORGANIC COMPOUNDS; ORGANS; RADIOACTIVE MATERIALS; RADIOISOTOPE SCANNING; RESPIRATORY SYSTEM; RODENTS; VERTEBRATES