Effects of age and sex on 125I-β-CIT binding to DAT

Objective: To investigate effects of age and sex on 125I-β-CIT binding to dopamine transporter (DAT). Methods: Detection of the differences in 125I-β-CIT binding kinetics in vivo between 6 week and 6 month old KM mice, and the differences of in vivo binding between female and male, and between 3 month and 12 month old SD rats.The animals were sacrificed 2 h after injection. Results: Uptake of 125I-β-CIT in the striatum, frontal cortex, parietal cortex, temporal cortex, occipital cortex, hippocampus, brain stem and whole brain in 6 week old mice was higher than that in 6 month old mice, and similar uptake pattern happened in between 3 month old and in 12 month old SD rats. In 12 months old SD rats, female rats had higher uptake in the striatum than male rats did. Conclusions: Young mice and rats have a higher uptake of 125I-β-CIT in the striatum than aged ones and female rats have a higher uptake than male ones do. This result indicates that the density of DAT in rat or mouse striatum may be reduced with aging