Correlation between 11C-CFT microPET/CT dopamine transporter imaging of striatum in Parkinson′s disease model rats and damage to dopamine neurons in the substantia nigra of midbrain / 中华核医学与分子影像杂志

ABSTRACT

Objective:To explore the correlations between 11C-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT) microPET/CT imaging and the degree of damage to dopamine neurons in the substantia nigra of midbrain and the severity of Parkinson′s disease (PD). Methods:Sixty male Sprague-Dawley (SD) rats were divided into PD model group ( n=48) and control group ( n=12) by random number table method. The PD model was established by injecting 6-hydroxydopamine (6-OHDA) into the right striatum. The rotational behavior test and 11C-CFT microPET/CT imaging were performed at 1, 2, 3 and 4 weeks after the establishment of PD model. The radioactivity uptake values of bilateral striatum were analyzed and the radioactivity uptake ratio of injured side to healthy side was calculated. The number of tyrosine hydroxylase (TH) immunoreactive positive neurons in the pars compacta of substantia nigra was counted by immunofluorescence staining, and the ratio of total number of TH positive neurons in injured side to healthy side was calculated. Data were analyzed by one-way analysis of variance, the least significant difference t test and Pearson correlation analysis. Results:At 1, 2, 3 and 4 weeks after the establishment of PD model, the rotation speed of PD model to the healthy side was (4.55±1.37), (8.64±1.64), (9.96±1.83) and (11.67±2.77) r/min, respectively, while there was no rotation behavior in the control group. Meanwhile, the ratios of 11C-CFT uptake and the number of TH positive neurons in the PD model group were 0.658±0.038, 0.580±0.094, 0.513±0.042, 0.394±0.065 and 0.698±0.066, 0.604±0.062, 0.546±0.064, 0.315±0.082, respectively, which were significantly lower than those in the control group (0.997±0.048 and 0.996±0.054; F values 167.50, 169.20, both P<0.05). Correlation analysis showed that 11C-CFT uptake ratio was correlated with rotation behavior (rotation speed) and TH positive neuron ratio ( r values -0.877, 0.897, both P<0.001). Conclusion:In the PD animal model, the ratios of 11C-CFT uptake has a good correlation with the degree of damage to dopamine neurons in the substantia nigra of the midbrain (TH positive neuron ratio) and the severity of PD.