MicroPET detection of enhanced 18F-FDG utilization by PKA inhibitor in awake rat brain.
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.
Hosoi
Rie
R
Course 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
Matsumura
Akira
A
Mizokawa
Shigekazu
S
Tanaka
Masaaki
M
Nakamura
Fusao
F
Kobayashi
Kaoru
K
Watanabe
Yasuyoshi
Y
Inoue
Osamu
O
D000777:Anesthetics / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D007839:Functional Laterality / Q000502:physiology; D008297:Male; D008657:Metabolic Clearance Rate; D023421:Models, Animal; D049268:Positron-Emission Tomography / Q000379:methods*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D019275:Radiopharmaceuticals / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013788:Thalamus / Q000187:drug effects / Q000378:metabolism; D013873:Thionucleotides / Q000494:pharmacology*; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology
D000777:Anesthetics; D001786:Blood Glucose; D047428:Protein Kinase Inhibitors; D019275:Radiopharmaceuticals; D013873:Thionucleotides; D019788:Fluorodeoxyglucose F18; C016957:adenosine-3',5'-cyclic phosphorothioate; D000242:Cyclic AMP