Loss of Dopamine Uptake Sites Labeled with sup3/supHGBR-12935 in Alzheimer’s Disease

摘要

The binding of the dopamine uptake inhibitor 3HGBR-12935 to postmortem putamen from a control group and patients with Alzheimer’s disease/senile dementia of Alzheimer type (AD/SDAT) or vascular dementia (VD) was studied. The binding density (Bmax) in AD/SDAT was significantly reduced to 50 of control. A reduction of Bmax in VD was also noted, but it did not reach statistical significance. No differences in apparent binding affinity (Kd) between controls and dementia groups were obtained. The concentrations of dopamine (DA), dihydroxyphe-nylacetic acid (DOPAC), 3-methoxytyramine (3-MT) and homovanillic acid were also determined. The concentrations of DA and DOPAC were reduced by 30–40 in AD/SDAT and VD, but the reductions did not reach statistical significance. The concentration of 3-MT was reduced by 40 in AD/SDAT and by 30 in VD. The 3HGBR-12935-binding densities correlated significantly with corresponding concentrations of DA in control brains. It is suggested that the loss of 3HGBR-12935-binding sites in human putamen in AD/SDAT reflects a degeneration of dopamine neuri