Absence of age-related dopamine transporter loss in current cocaine abusers
- Brookhaven National Lab., Upton, NY (United States); and others
The brain dopamine (DA) system appears to play a crucial role in the reinforcing properties of cocaine. Using PET we had previously shown significant decreases in DA D2 receptors but no changes in DA transporters (DAT) in detoxified cocaine abusers (>1 month after last cocaine use). This study evaluates DAT availability in current cocaine abusers (15 male and 5 female; age = 36.2{+-}5.3 years old) using PET and [C-11]cocaine, as a DAT ligand, and compares it to that in 18 male and 2 female age matched normal controls. Cocaine abusers had a history of abusing 4.2{+-}2.8 gm /week of cocaine for an average of 11.0{+-}4.9 years and their last use of cocaine was 5.4{+-}8 days prior to PET study. DAT availability was obtained using the ratio of the distribution volume in the region of interest (caudate, pulamen) to that in cerebellum which is a function of Bmax./Kd.+1. DAT availability in cocaine abusers did not differ to that in normals (N) (C= 1.78{+-}0.14, N= 1.77{+-}0.13). In addition, there were no differences between the groups in the distribution volume or the Kl (plasma to brain transfer constant) measures for [C-11]cocaine. However, in the normals but not in the abusers striatal DAT availability decreased with age (C: r = -0.07, p = 0.76; N: r = -0.55, p < 0.01). Though this study fails to show group differences in DAT availability between normals and current cocaine abusers it indicates a blunting of the age-related decline in DAT availability in the cocaine abusers. Future studies in older cocaine abusers at different time after detoxification arc required in order to assess if cocaine slows the loss of DAT with age or whether these changes reflect compensation to increased DAT blockade and recover with detoxification.
- OSTI ID:
- 563331
- Report Number(s):
- CONF-970602-; ISSN 0161-5505; TRN: 97:004028-0003
- Journal Information:
- Journal of Nuclear Medicine, Vol. 38, Issue Suppl.5; Conference: 44. annual meeting of the Society of Nuclear Medicine, San Antonio, TX (United States), 2-5 Jun 1997; Other Information: PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
Decreased dopamine activity predicts relapse in methamphetamine abusers
Trans-synaptic (GABA-dopamine) modulation of cocaine induced dopamine release: A potential therapeutic strategy for cocaine abuse