Characteristic brain distribution of 1-(14)C-octanoate in a rat model of focal cerebral ischemia in comparison with those of (123)I-IMP and (123)I-iomazenil.
J Nucl Med
; 44(7): 1168-75, 2003 Jul.
Article
em En
| MEDLINE
| ID: mdl-12843233
ABSTRACT
UNLABELLED 1-(11)C-Octanoate is a potential tracer for studying astroglial function in PET. To evaluate the usefulness of 1-(11)C-octanoate for studying ischemic stroke, we investigated the brain distribution of 1-(14)C-octanoate and compared it with N-isopropyl-p-(123)I-iodoamphetamine ((123)I-IMP) distribution (cerebral blood flow), (123)I-iomazenil ((123)I-IMZ) distribution (neuronal viability based on (123)I-IMZ binding to benzodiazepine receptors), and hematoxylin-eosin stain (morphologic changes) in a rat model of focal cerebral ischemia. METHODS:
The right middle cerebral artery of each rat was occluded intraluminally. The brain distribution of 1-(14)C-octanoate and (123)I-IMP (or (123)I-IMZ) was determined 4 and 24 h after the insult using a dual-tracer autoradiographic technique (n = 4-7 in each group). Coronal brain sections adjacent to those used for autoradiography were stained with hematoxylin and eosin. Regions of interest (ROIs) were determined for 3 coronal slices, and asymmetry indices (AIs, lesion/normal hemisphere) of the tracer uptake were calculated. ROIs on the hemisphere with the lesion were classified into 4 groups In region A, widespread necrotic cells were observed; in region B, necrotic cells were occasionally observed; in region C1, no morphologic changes were observed and the AIs for (123)I-IMP (or (123)I-IMZ) wereRESULTS:
1-(14)C-Octanoate uptake decreased in the regions where morphologic changes were observed (regions A and B) but was relatively preserved in the surrounding region without morphologic changes despite reduced (123)I-IMP and (123)I-IMZ uptake (region C1). In the region without morphologic changes (region C1), AIs for 1-(14)C-octanoate were significantly higher than those for (123)I-IMP (4 h, 0.73 +/- 0.23 for 1-(14)C-octanoate and 0.37 +/- 0.20 for (123)I-IMP, P < 0.0001; 24 h, 0.84 +/- 0.11 for 1-(14)C-octanoate and 0.44 +/- 0.15 for (123)I-IMP, P < 0.0001) and those for (123)I-IMZ (4 h, 0.83 +/- 0.19 for 1-(14)C-octanoate and 0.57 +/- 0.13 for (123)I-IMZ, P < 0.0001; 24 h, 0.91 +/- 0.13 for 1-(14)C-octanoate and 0.73 +/- 0.06 for (123)I-IMZ, P < 0.0001).CONCLUSION:
1-(14)C-Octanoate uptake was relatively preserved in the regions without morphologic changes despite reduced (123)I-IMP and (123)I-IMZ uptake. 1-(11)C-Octanoate may provide further functional information on the pathophysiology of ischemic stroke, reflecting astroglial function based on fatty acid metabolism.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
/
Caprilatos
/
Isquemia Encefálica
/
Flumazenil
/
Iofetamina
Tipo de estudo:
Evaluation_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Nucl Med
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Japão