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This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Wang, G.-J. Articles by Gatley, S. PubMed Articles by Wang, G.-J. Articles by Gatley, S.

Decreased dopamine D2 receptors and transporter in spontaneously obese bonnet macaques

¹ Medical Department, Bldg 40, Brookhaven National Laboratory, Upton, New York; ² SUNY Downstate Medical Center, Brooklyn, New York; ³ NIAAA/NIDA, Rockville, Maryland; ⁴ Northeastern University, Boston, Massachusetts

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Objectives: Using PET we showed that morbidly obese human subjects had lower levels of striatal dopamine (DA) D2 receptors (D2R) than non-obese control subjects. To determine whether these findings apply to anesthetized non-human primates, we used PET studies to assess synaptic DA D2 receptors and transporters in 8 spontaneously obese adult female bonnet macaques (OBM) compared to 6 age-matched non-obese controls (CM; BMI 46 ±7 vs 23 ±2).

Methods: Using isoflurane and nitrous anesthesia we performed PET with [C-11]raclopride (D2R) and [C-11]cocaine [DA transporter (DAT)] availability twice to assess variability. Regions of interest were defined in the striatum and cerebellum. Measures of D2R and DAT availability (Bmax/Kd) were calculated using the distribution volume of striatum to that in cerebellum -1.

Results: Test-retest variability for [C-11]raclopride was 0.5 ± 9.6%; for [C-11]cocaine it was 5.6 ±11.5%. There was a trend toward larger test-retest variability for the [C-11]raclopride binding measures among OBM (p<0.06). DAT and D2R availability were significantly correlated in the left striatum (r=.59, p<0.02). OBM had significant lower D2R availability (2.65±0.21) in the right striatum than CM (2.89±0.2, p <0.05). Striatal DAT availability in OBM (1.11±0.24) was also lower than CM (1.37±0.17, p<0.04).

Conclusions: Lower D2R availability in the anesthetized obese macaques compared to non-obese controls replicates our findings in humans and in rodents. Furthermore obese macaques exhibited lower DAT availability. These findings highlight the involvement of the dopamine system in obesity.

Research Support: DOE/OBER and NIAAA/NIDA.

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Wang, G.-J. Articles by Gatley, S. PubMed Articles by Wang, G.-J. Articles by Gatley, S.