Regional brain uptake and retention of Tc-99m-propylene amine oxime derivatives
Tc-99m-propylene amine oxime (Tc-99m-PnAO) is a neutral lipophilic chelate that rapidly and passively enters the cerebral cortex (80% on first pass in baboon brain) and then clears exponentially leaving inadequate activity to perform conventional SPECT brain imaging. When side chains are attached to the PnAO backbone lipophilicity is increased, as well as brain retention. In this work the authors evaluated regional brain uptake and retention of Tc-99m-PnAO and several of its derivatives in rat brain using serial autoradiography (ARG). Autoradiographs of each Tc-99m chelate at 5 sec. post peak brain uptake demonstrate discrete grey to white matter differentiation. White matter tracts are well delineated and the darker areas of grey matter appearing in the midbrain and thalamus, corresponding to areas of high capillary density and high blood flow documented with C-14-iodoantipyrine, are easily distinguished. Within 5 min. of the peak uptake the regional uptake and grey/white differentiation is lost on the Tc-99m-PnAO ARG. In contrast the 5 min. ARG of the more lipophilic Tc-99m, chelate with dimethyl-PnAO (DMPnAO) shows the complete reverse of the 5 sec. ARG, with greater activity in the white matter tracts than in the grey matter. One of the derivatives, tetramethyl-PAO (TMPAO) complexed with Tc-99m is retained in the grey matter of rat brain and shows persistent grey to white localization for at least 60 min., analogous to what has been reported with I-123-IMP. These results suggest that Tc-99m-TMPAO or one of its derivatives may be appropriate for SPECT imaging of cerebral blood flow abnormalities.
- Research Organization:
- Univ. of Missouri, Columbia, MO
- OSTI ID:
- 6760920
- Report Number(s):
- CONF-850611-; TRN: 87-010624
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 26:5; Conference: 32. annual meeting of the Society of Nuclear Medicine, Houston, TX, USA, 2 Jun 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMINES
BIOCHEMISTRY
LABELLING
BRAIN
AUTORADIOGRAPHY
BLOOD FLOW
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
RADIOPHARMACEUTICALS
EVALUATION
TISSUE DISTRIBUTION
UPTAKE
TECHNETIUM COMPLEXES
BABOONS
BIOLOGICAL LOCALIZATION
CEREBRAL CORTEX
CHELATES
DIAGNOSTIC USES
IODINE 123
OXIMES
RATS
RETENTION FUNCTIONS
TECHNETIUM 99
THALAMUS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CENTRAL NERVOUS SYSTEM
CEREBRUM
CHEMISTRY
COMPLEXES
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EMISSION COMPUTED TOMOGRAPHY
FUNCTIONS
HOURS LIVING RADIOISOTOPES
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MONKEYS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PRIMATES
RADIOISOTOPES
RODENTS
TECHNETIUM ISOTOPES
TOMOGRAPHY
TRANSITION ELEMENT COMPLEXES
USES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics