【摘要】   目的   利用¹⁸氟-氟脱氧葡萄糖(¹⁸F-FDG)小动物正电子发射计算机断层显像（micro PET）研究糖尿病小鼠心肌葡萄糖代谢的改变。 方法   取正常野生型BKS小鼠5只、db/db糖尿病小鼠5只，正常进食，控制氧流量400 ml/min，分别在1.5%～1.8%异氟烷麻醉下尾静脉弹丸式注射50～75 µl ¹⁸F-FDG 200～300 uci（7.4～11.1 MBq）进行microPET动态显像60 min，图像重建后勾画心肌感兴趣区（ROI）获取心肌时间-放射性曲线（TAC），计算心肌葡萄糖标准摄取值（SUV），同时经小鼠尾静脉多点采血获取尾静脉血TAC，利用输入函数数学模型显像分析系统（KIS），计算两组小鼠心肌的葡萄糖代谢率MRGlu），进行t检验。 结果    显像45～55 min 与BKS鼠比较,db/db鼠SUV、Ki值 [(5.70±1.19)vs(12.92±1.68) g/ml，P＜0.01]，[(0.09±0.02)vs(0.20±0.05) ml/(min·g),P＜0.01] 降低；平均血糖、葡萄糖代谢率 [(24.39±3.36)vs(6.10±1.31) mmol/L,   P＜0.01],[ (40.14±4.32)vs( 21.01±2.98) mg/kg·min, P＜0.01] 升高。 结论   ¹⁸F-FDG micro PET显像可提示db/db糖尿病小鼠心肌葡萄糖摄取及代谢率的改变。

   【关键词】 db/db小鼠；¹⁸氟-氟脱氧葡萄糖；小动物正电子发射计算机断层；心肌显像；葡萄糖代谢率；标准摄取值

  【Abstract】  Objective  To investigate the changes of myocardial glucose metabolism in mice with diabetes mellitus by ¹⁸ F - fluorodeoxyglucose (18F-FDG) small animal positron emission tomography (micro PET).  Methods  5 wild-type BKS mice and 5 db/db mice were fed routinely. All the mice underwent microPET dynamic imaging for 60 mins after intravenous bolus injection of 50~75 μl ¹⁸F-FDG 200-300 uci（7.4-11.1 MBq）, using 1.5%~1.8% isoflurane for anesthesia and controlling the oxygen flow rate 400 ml/min. After image reconstruction, myocardial time-activity curves (TAC) were obtained by drawing the regions of interest (ROI) and myocardial glucose standardized uptake value (SUV) was calculated. Meanwhile, tail venous blood were collected at different time points to draw the blood TAC. The rates of myocardial glucose metabolism (MRGlu) were calculated by the input function mathematical model and kinetic imaging analysis system (KIS) and compared using T test.  Results  The SUV and Ki values were significantly lower [(5.70±1.19 vs (12.92±1.68)g/ml，P<0.01;（0.09±0.02）vs（0.20±0.05） ml/(min·g), P＜0.01]and mean plasma glucose (MPG) and MRGlu were significantly higher [ (24.39±3.36 ) vs (6.10±1.31)mmol/L, P＜0.01; (40.14±4.32) vs (21.01±2.98)mg/kg·min, P＜0.01]in db/db mice than in BKS mice at 45~55 min after 18F-FDG injection.  Conclusion  ¹⁸F-FDG microPET imaging showed that myocardial glucose uptake rates and metabolic rates of db / db diabetic mice were significantly changed.

    【Key words】 db/db mice; ¹⁸F-FDG; MicroPET; Myocardial imaging; Glucose metabolic rate (MRGlu); Standardized uptake value (SUV)