Assessment of effects of 7, 8-dihydroxyflavone on the striatum in normal cynomolgus monkeys with 99Tcm-TRODAT-1 SPECT/CT imaging

Abstract

Objective To assess the effects of 7, 8-dihydroxyflavone (7, 8-DHF) on the striatum (ST) in normal cynomolgus monkeys using 99Tcm-TRODAT-1 imaging. Methods A total of six healthy female cynomolgus monkeys were included in this study. Three of them were fed with normal food (control group), and the other three were given oral administration of 7, 8-DHF in addition to normal food (experimental group). The SPECT/CT imaging was performed at different time after 99Tcm-TRODAT-1 injection. The ROI of ST was drawn on images of 3 consecutive transverse slices that could be visualized best. The cerebellum (CB) was taken as the background reference area. The radioactivity uptake ratios of ST/CB at 1, 3, 4 and 5 h were calculated respectively. Paired-t test was used to analyze the data. Results ST radioactive uptake ratios showed continuing increase on the delay images. ST/CB uptake ratios of the control group at 1, 3, 4 and 5 h were 1.43±0.04, 1.82±0.06, 2.04±0.12, 2.42±0.23, respectively, and those of the experimental group were 1.35±0.08, 2.40±0.09, 2.74±0.13 and 3.25±0.15 respectively. There was no significant difference between the two groups at 1 h (t=2.57, P>0.05), while ST/CB uptake ratios of the experimental group at 3, 4 and 5 h were significantly higher (t values: 2.77, 2.87 and 2.92, all P<0.05). Conclusion 99Tcm-TRODAT-1 SPECT/CT imaging can be used to assess the DAT activation effect by 7, 8-DHF on ST of cynomolgus monkeys. Key words: Corpus striatum; Dopamine plasma membrane transport proteins; Flavones; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Macaca fascicularis; TRODAT-1