Reduced striatal dopamine transporter levels in heroin dependent subjects

Objectives To explore the relation between dopamine transporter (DAT) and heroin addiction, we assessed the DAT levels in the striatum by 99mTc-TRODAT-1 SPECT (single photon emission computed tomography) brain imaging in heroin addicts.

Methods 29 healthy controls and 72 abstinent heroin-dependent subjects were recruited. These heroin-dependent subjects underwent physiological detoxification for two weeks and negative results from urine tests. All subjects were performed with 99mTc-TRODAT-1SPECT brain imaging at 2-3 hours after iv. Specific tracer uptake ratios (SURs) in the striatum were assessed by the use of the region of interest (ROI). SURs was calculated as follows:[(target- OC)/ OC].

Results 29 healthy controls, 15 males and 14 females, aged 31.55±7.80 years (19-43 years). Abstinent heroin-dependent subjects, 60 males and 12 females, aged 37.71±8.91 years (24-55 years). Heroin intake dosage was 1.01±0.62 g/d (0.1-3.0 g/d) and mean duration of use was 7.81±4.32 years (0.08-18.25 years). A significant SURs reduction in heroin abusers compared with controls was found in the right striatum (1.28±0.26 and 1.94±0.37, P<0.01), left striatum (1.31±0.25 and 1.91±0.39, P<0.01), right putamen (1.28±0.26 and 1.87±0.36, P<0.01), left putamen (1.31±0.25 and 1.86±0.37, P<0.01), right caudate nucleus (1.28±0.27 and 2.00±0.39, P<0.01) and left caudate nucleus (1.30±0.26 and 1.96±0.40, P<0.01). And these DAT levels have the negative correlation with the usual intake amount and duration of heroin abuse (P<0.05).

Conclusions This study results indicated that abstinent heroin dependent subjects had a lower DAT levels in the striatum than health controls. These findings suggested that chronic heroin abuse may impair the striatal dopamine neuron.

Research Support The National Science and Technology Support Plan Project of China (2008BAI49B04