[1-11C]Octanoate as a PET tracer for studying ischemic stroke: evaluation in a canine model of thromboembolic stroke with positron emission tomography.
Octanoate is taken up by the brain and converted in astrocytes to glutamine through the TCA cycle after beta-oxidation. Consequently, [1-11C]octanoate might serve as a useful positron emission tomography (PET) probe for studying cerebral oxidative metabolism and/or astroglial functions. The present study attempted to evaluate the utility of using [1-11C]octanoate as a PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. We used a canine model of thromboembolic stroke. Five male beagle dogs were implanted with an indwelling catheter in the left internal carotid artery. A single autologous blood clot was injected into the left internal carotid artery through the catheter. The brain distribution of [1-11C]octanoate and cerebral blood flow (CBF) were determined 24 h after insult using a high resolution PET scanner. Post mortem brain regions unstained with 2,3,5-triphenyltetrazolium chloride (TTC) were defined as infarcts. In the region of an infarct, accumulation of [1-11C]octanoate decreased concurrently with CBF reduction. In contrast, normal accumulation of [1-11C]octanoate was observed in ischemic but vital regions, suggesting that an increased accumulation of [1-11C]octanoate relative to CBF takes place in these regions. In conclusion, [1-11C]octanoate accumulated in ischemic but vital regions, indicating that [1-11C]octanoate is a potentially useful PET tracer for imaging and evaluating the pathophysiology of ischemic stroke.
Kuge
Y
Y
Institute for Biofunctional Research Co., Inc., Osaka, Japan. kuge@med.hokudai.ac.jp
Kawashima
H
H
Minematsu
K
K
Hasegawa
Y
Y
Yamaguchi
T
T
Miyake
Y
Y
Hashimoto
T
T
Imanishi
M
M
Shiomi
M
M
Tamaki
N
N
Hashimoto
N
N
D000818:Animals; D002210:Caprylates; D002560:Cerebrovascular Circulation; D004195:Disease Models, Animal; D004285:Dogs; D008297:Male; D019275:Radiopharmaceuticals; D013923:Thromboembolism / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed
D002210:Caprylates; D019275:Radiopharmaceuticals; C031492:octanoic acid