Short Communications

Annals of Nuclear Medicine

, Volume 14, Issue 1, pp 69-74

First online:

Preliminary evaluation of [1-11C]octanoate as a PET tracer for studying cerebral ischemia: A PET study in rat and canine models of focal cerebral ischemia

  • Yuji KugeAffiliated withInstitute for Biofunetional Research Co., Ltd.Department of Tracer Kinetics, Hokkaido University School of Medicine Email author 
  • , Hidefumi KawashimaAffiliated withInstitute for Biofunetional Research Co., Ltd.
  • , Tadatoshi HashimotoAffiliated withTakeda Chemical Industries Co., Ltd.
  • , Mitsuaki ImanishiAffiliated withTakeda Chemical Industries Co., Ltd.
  • , Mie ShiomiAffiliated withTakeda Chemical Industries Co., Ltd.
  • , Kazuo MinematsuAffiliated withCerebrovascular Division, Department of Medicine, National Cardiovascular Center
  • , Yasuhiro HasegawaAffiliated withCerebrovascular Division, Department of Medicine, National Cardiovascular Center
  • , Takenori YamaguchiAffiliated withCerebrovascular Division, Department of Medicine, National Cardiovascular Center
  • , Yoshihiro MiyakeAffiliated withInstitute for Biofunetional Research Co., Ltd.
    • , Naoto HashimotoAffiliated withInstitute for Biofunetional Research Co., Ltd.

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Octanoate is taken up into the brain and is converted in astrocytes to glutamine through the TCA cycle after β-oxidation. We speculate that [1-11C]octanoate may be used as a tracer for astroglial functions and/or fatty acid metabolism in the brain and may be useful for studying cerebral ischemia. In the present study we investigated brain distribution of [1-11C]octanoate and compared it with cerebral blood flow (CBF) by using rat and canine models of middle cerebral artery (MCA) occlusion and a high resolution PET. In rats brain distribution of [15O]H2O measured 1–2 h and 5–6 h after insult was compared with that of [1-11C]octanoate measured 3–4 h after insult. Radioactivity ratios of lesioned to normal hemispheres determined with [15O]H2O were lower than those determined with [1-11C]octanoate. These results were confirmed by a study on a canine model of MCA-occlusion. Twenty-four hours after insult, CBF decreased in the MCA-territory of the occluded hemisphere, whereas normal or higher accumulation of [1-11C]octanoate was observed in the ischemic regions. The uptake of [1-11C]octanoate-derived radioactivity therefore increased relative to CBF in the ischemic regions, indicating that [1-11C]octanoate provides functional information different from CBF. In conclusion, we found that [1-11C]octanoate is a potential radiopharmaceutical for studying the pathophysiology of cerebral ischemia.

Key words

[1-11C]octanoate positron emission tomography cerebral ischemia rat dog