^(18)氟-氟脱氧葡萄糖小动物正电子发射计算机断层显像观察糖尿病小鼠心肌葡萄糖代谢的改变

Changes of myocardial glucose metabolism in mice with diabetes mellitus by ^(18)F-FDG micro PET

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)观察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400ml/min,分别在1.5%~1.8%异氟烷麻醉下尾静脉弹丸式注射50~75μl18F-FDG 200~300uci(7.4~11.1MBq)进行micro PET动态显像60min,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),计算两组心肌的葡萄糖代谢率(MRGlu),并行t检验。结果与BKS小鼠比较,db/db小鼠显像45~55min SUV、Ki值[(12.92±1.68)vs(5.70±1.19)g/ml,P<0.01],[(0.20±0.05)vs(0.09±0.02)ml/(min·g),P<0.01]降低;平均血糖、葡萄糖代谢率[(6.10±1.31)vs(24.39±3.36)mmol/L,(21.01±2.98)vs(40.14±4.32)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。

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 5wild-type BKS mice and 5db/db mice were fed routinely.All the mice underwent micro PET dynamic imaging for 60 mins after intravenous bolus injection of 50~75μl 18F-FDG 200~300uci（7.4~11.1 MBq）,using 1.5%~1.8%isoflurane for anesthesia and controlling the oxygen flow rate400ml/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[（12.92±1.68）vs（5.70±1.19）g/ml,P〈0.01;（0.20±0.05）vs（0.09±0.02）ml/（min·g）,P〈0.01]and mean plasma glucose（MPG）and MRGlu were significantly higher[（6.10±1.31）vs（24.39±3.36）mmol/L,P〈0.01;（21.01±2.98）vs（40.14±4.32）mg/（kg·min）,P〈0.01]in db/db mice than in BKS mice at 45~55min after 18F-FDG injection. Conclusion 18 F-FDG micro PET imaging showed that myocardial glucose uptake rates and metabolic rates of db/db diabetic mice were significantly changed.