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Updated: Aug 19, 2026
Non-invasive Imaging and Analysis of Cerebral Ischemia in Living Rats Using Positron Emission Tomography with 18F-FDG
Published on: December 28, 2014
MicroPET detection of enhanced 18F-FDG utilization by PKA inhibitor in awake rat brain
Rie Hosoi1, Akira Matsumura, Shigekazu Mizokawa
1Course of Allied Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan. hosoi@sahs.med.osaka-u.ac.jp
Abstract:
To obtain PET imaging of glucose metabolism in the brains of conscious rats, a method of rat head fixation was developed. PET measurement with microPET was performed for 60 min after 18F-FDG injection. Significant enhancement of glucose utilization in the right striatum was observed with infusion of Rp-adenosine-3,5-cyclic phosphorothioate triethylamine (Rp-cAMPS). FDG uptake increments were also seen in the ipsilateral frontal cortex and thalamus. As initial FDG uptake in the brain was not significantly altered by Rp-cAMPS, increased glucose metabolism might be due to an increase in the phosphorylation rate by hexokinase rather than the delivery process from plasma to the brain. In contrast to awake rats, the effect of Rp-cAMPS was abolished by anesthesia using chloral hydrate, indicating that neuronal activity has an important role in short term regulation of hexokinase activity through the cAMP/PKA system in the brain. These results strongly demonstrated the value of measuring glucose utilization in the brains of conscious rats.
Insights
Conscious rats show enhanced brain glucose metabolism with Rp-adenosine-3,5-cyclic phosphorothioate triethylamine (Rp-cAMPS) infusion. This effect, mediated by neuronal activity, highlights the importance of studying brain metabolism in awake animals.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Studying brain metabolism in conscious animals is crucial for understanding neurological functions.
- Previous methods for brain imaging in conscious rodents have limitations.
Purpose of the Study:
- To develop a method for positron emission tomography (PET) imaging of glucose metabolism in the brains of conscious rats.
- To investigate the effects of Rp-adenosine-3,5-cyclic phosphorothioate triethylamine (Rp-cAMPS) on brain glucose utilization.
Main Methods:
- Developed a rat head fixation technique for PET imaging.
- Administered 18F-FDG and performed microPET measurements for 60 minutes.
- Infused Rp-cAMPS in conscious rats and compared with anesthetized rats.
Main Results:
- Significant enhancement of glucose utilization in the right striatum of conscious rats after Rp-cAMPS infusion.
- Increased FDG uptake observed in the ipsilateral frontal cortex and thalamus.
- Rp-cAMPS effect was abolished by chloral hydrate anesthesia, indicating a role for neuronal activity.
Conclusions:
- Rp-cAMPS increases brain glucose metabolism in conscious rats, likely by enhancing hexokinase phosphorylation.
- Neuronal activity plays a key role in the short-term regulation of hexokinase activity via the cAMP/PKA system.
- Measuring glucose utilization in conscious rats is valuable for neuroscience research.
