用^(18)F-FDG和^(99)Tc^m-MIBI显像评估冷冻心肌骨髓CD34^+细胞移植后代谢和灌注的变化

To evaluate the changes of metabolism and perfusion of infarcted myocardium implanted bone marrow CD34^+ cells using ^(18)F-FDG and ^(99)Tc^m-MIBI

目的 用1 8F 脱氧葡萄糖 (FDG)、99Tcm 甲氧基异丁基异腈 (MIBI)评价犬冷冻心肌骨髓CD34+ 细胞移植后心肌代谢和灌注的变化。方法 1 2只杂种犬分为细胞移植组和对照组。用免疫磁珠法从犬肋骨骨髓分离CD34+ 细胞并注射到用CO2 冷冻建立的慢性心肌梗死模型区 ,对照组注射伊思考夫改良杜尔贝可培养基 (IMDM)培养液。分别于建立模型前、后 4周和干细胞移植后 8周行1 8F FDG和99Tcm MIBI心肌显像 ,评价细胞移植结果 ,计算冷冻心肌代谢与灌注显像的F值。干细胞移植后 8周取心肌做第 8因子免疫组织化学和病理检查。结果 正常心肌代谢与灌注显像清晰 ,F值接近 0 ,干细胞移植前、后 8周冷冻心肌1 8F FDG与99Tcm MIBI显像的F值分别为 5 . 5 0± 1 . 31 ,5 4 4± 0 . 70与 1 1 7±0. 4 1 ,1 . 5 0± 0 . 5 5 (P <0 . 0 1 ) ;对照组为 5 . 5 3± 0. 80 ,5. 5 4± 1 . 2 9与 5. 0 0± 1 . 5 5 ,5 . 0 8± 1. 4 6 (P >0 . 0 5 ) ,骨髓CD34+ 细胞移植使冷冻心肌的代谢与灌注明显得到恢复。干细胞移植后 8周冷冻区血管密度高于对照组 (P <0 . 0 1 )。结论 骨髓CD34+ 细胞移植后冷冻区存在大量活的心肌细胞。

Objective To evaluate the changes of metabolism and perfusion of freezing induced infarction myocardium implanted bone marrow CD34 + cells using 18 F fluorodeoxyglucose (FDG) and 99 Tc m methoxyisobutylisonitrile (MIBI). Methods Twelve dogs were randomly divided into cell transplantation and control group. In cell transplantation group bone marrow CD34 + cells were separated and purified with immunomagnetic separation methods and implanted into the chronic cryoinjured myocardium site; and in control group IMDM culture fluid without cells was injected into the chronic cryoinjured myocardium site. Myocardial perfusion imaging was evaluated by 99 Tc m MIBI SPECT and metabolic imaging was evaluated by 18 F FDG imaging before and 4 weeks after myocardium infarction and 8 weeks after cells transplantation. F values of reduced myocardial segments of myocardial perfusion and 18 F FDG uptake were calculated. Immunohistochemistry and electron microscopy study were made. Results The images of 99 Tc m MIBI and 18 F FDG on normal myocardium were clear. F values of myocardial perfusion were 1.17±0.41, 1.50±0.55 and 18 F FDG uptake 5.50±1.31, 5.44±0.70 in cell transplantation group ( P <0.01) before and 8 weeks after transplantation; 5.00±1.55, 5.08±1.46 and 5.53±0.80, 5.54±1.29 in control group ( P >0.05). The vascular density in cell transplantation group was higher than that in the control group ( P <0.01). Conclusion Bone marrow CD34 + cells,after being implanted into the chronic cryoinjured myocardium, could obviously improve the vascularization and coronary perfusion and recover the glycometabolism showing that there were many living myocardial cells in the chronic cryoinjured myocardium site.