Measurement of glucose metabolism in rat spinal cord slices with dynamic positron autoradiography

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• 作者：Xiaoping Fan ; Tatsuya Asai ; Koichi Morioka ; Kenzo Uchida ; Hisatoshi Baba ; Kuniyoshi Tanaka ; Jian Zhuang ; Hidehiko Okazawa ; Yasuhisa Fujibayashi
• 关键词：Spinal cord ; [¹⁸F]fluoro-deoxyglucose ([¹⁸F]FDG) ; Positron emission tomography ; Autoradiography ; Rat
• 刊名：Nuclear Medicine and Biology
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：36
• 期：2
• 页码：183-189
• 全文大小：633 K

文摘

We attempted to measure the regional metabolic rate of glucose (MRglc) in sliced spinal cords in vitro. The thoracic spinal cord of a mature Wister rat was cut into 400-μm slices in oxygenated and cooled (1–4°C) Krebs-Ringer solution. After at least 60 min of preincubation, the spinal cord slices were transferred into double polystyrene chambers and incubated in Krebs-Ringer solution at 36°C, bubbled with 5 % O₂/5 % CO₂ gas. To measure MRglc, we used the dynamic positron autoradiography technique (dPAT) with F-18-2-fluoro-2-deoxy-d-glucose ([¹⁸F]FDG) and the net influx constant of [¹⁸F]FDG as an index. Uptake curves of [¹⁸F]FDG were well fitted by straight lines for more than 7 h after the slicing of the spinal cord (linear regression coefficient, r=0.99), indicating a constant uptake of glucose by the spinal cord tissue. The slope (K), which denotes MRglc, is affected by tetrodotoxin, and high K⁺ (50 mM) or Ca²⁺-free, high Mg²⁺ solution. After 10 min of hypoxia, the K value following reoxygenation was similar to the unloaded control value, but after 45 min of hypoxia, the K value was markedly lower than the unloaded control value, and after >90 min of reoxygenation it was nearly 0. Our results indicate that the living spinal cord slices used retained an activity-dependent metabolism to some extent. This technique may provide a new approach for measuring MRglc in sliced living spinal cord tissue in vitro and for quantifying the dynamic changes in MRglc in response to various interventions such as hypoxia.