Evaluation of dopamine transporter density in healthy Brazilians using Tc-99m TRODAT-1 SPECT

The presynaptic dopamine transporter (DAT) modulates the uptake of dopamine by regulating its concentration in the central nervous system. We aimed to evaluate the DAT binding potential (DAT-BP) in a sample of healthy Brazilians through technetium-99 metastable TRODAT-1 single-photon emission computed tomography imaging. We selected 126 healthy individuals comprising 72 men and 54 women, aged 18 to 80 years. We conducted semi-quantitative evaluation in transaxial slices, following which we identified the regions of interest in the striatal region using the occipital lobe as a region of non-specific DAT-BP. We found a decrease in DAT-BP in healthy individuals aged over 30 years, culminating in a 42% mean reduction after 80 years. There was no difference in the decrease by age group between the right (linear regression test [R-2] linear = 0.466) and left striatum (R-2 linear = 0.510). Women presented a higher DAT-BP than men (women: R-2 linear = 0.431; men: R-2 linear = 0.457); nonetheless, their decrease by age group was equal to that in men. Our study sheds light on important DAT-BP findings in healthy Brazilian subjects. Our results will facilitate understanding of brain illnesses that involve the dopamine system, such as neuropsychiatric disorders.

Automated summary

The study evaluated the DAT binding potential in healthy Brazilians using TRODAT-1 imaging, finding a decrease in DAT-BP with age. Women had higher DAT-BP than men, but both genders showed equal decrease in DAT-BP with age.