Effect of cocaine and amphetamine on ¹⁸FDG uptake by murine heart and brown adipose tissue (BAT)

Objectives Cocaine is a dopamine reuptake inhibitor, a norepinephrine reuptake inhibitor and a serotonin reuptake inhibitor. Amphetamine acts by increasing the levels of norepinephrine, serotonin, and dopamine in the brain. Since norepinephrine is involved in BAT activation, we examined the effect of cocaine or amphetamine injection, separately or together, on uptake of ¹⁸FDG by BAT in mice.

Methods Male CD-1 mice (25-28g) were fasted overnight and then injected intraperitoneally with either cocaine (20 mg/kg), amphetamine (15 mg/kg) or the two drugs together. Mice injected with saline served as controls. Two hours later unanesthetized animals were injected with ¹⁸FDG (50μCi) via tail vein. One hr later, the animals were sacrificed and complete biodistribution was measured. The results were calculated as %ID/g (mean ± sem, n=6-10/group).

Results The combination of cocaine and amphetamine injection produced dramatic hyperactivity in the mice and stimulated ¹⁸FDG uptake in heart and BAT (p<0.01). In contrast, both treatments stimulated ¹⁸FDG uptake in the heart(p<0.01) but only amphetamine increased uptake in BAT(p<0.05). No other significant effects on ¹⁸FDG uptake by any of the other tissues that were sampled was noted. Blood glucose for all groups averaged 80 mg%.

Conclusions The combination of cocaine and amphetamine appear to have a stimulatory effect on BAT uptake of ¹⁸FDG in mice. The mechanism(s)for this stimulation are under investigation.

Research Support Shriners Hospital for Children, Bosto

• Download figure
• Open in new tab
• Download powerpoint

*p<0.01