Xiao Zhuang-wei, Cao Chu-yu, Wang Zhao-xin, Li Jun-xiong, Liao Hai-yong, Zhang Xue-xin
Department of Radiology, First Affiliated Hospital of Shantou University Medical College, Shantou 515041, China.
Chin Med J (Engl). 2006 Nov 5;119(21):1802-7.
Although dopamine transporter (DAT) is essential for addiction, the effect of additive drugs on DAT function is still controversial, especially for opiates. We investigated the functional changes of dopamine transporter in striatum of rhesus monkeys during acute morphine injection and its abstinence.
Four rhesus monkeys, 6 to 9 years old, two male and two female, were examined for 12 days. Single photon emission computed tomography (SPECT) was performed with (99)T(cm)-TRODAT-1 as the radiopharmaceutical dopamine transporter agent during different stages of acute morphine injection and its abstinence. The ratios of SPECT signal between striatum and cerebellum (ST/CB) were calculated.
The ST/CB ratio declined significantly on the first day of morphine injection and continued declining with more morphine injections. After abstinence, the ratio increased with time, but was still significantly lower on the 5th day of abstinence than the normal level.
In rhesus monkey, acute morphine injection has both rapid and lasting effects on DAT by downregulating its function. The decline was partially reversible following morphine abstinence. The results suggest that striatum is one effective target of morphine and that the DAT function in striatum is one indicator for morphine addiction.
尽管多巴胺转运体（DAT）对成瘾至关重要，但成瘾性药物对DAT功能的影响仍存在争议，尤其是对于阿片类药物。我们研究了恒河猴在急性注射吗啡及其戒断期间纹状体中多巴胺转运体的功能变化。
对4只6至9岁的恒河猴（2只雄性和2只雌性）进行了12天的检查。在急性注射吗啡及其戒断的不同阶段，使用（99）锝-TRODAT-1作为放射性药物多巴胺转运体试剂进行单光子发射计算机断层扫描（SPECT）。计算纹状体与小脑之间的SPECT信号比值（ST/CB）。
吗啡注射第一天ST/CB比值显著下降，随着吗啡注射量增加持续下降。戒断后，该比值随时间增加，但在戒断第5天时仍显著低于正常水平。
在恒河猴中，急性注射吗啡通过下调其功能对DAT产生快速且持久的影响。吗啡戒断后这种下降部分可逆。结果表明纹状体是吗啡的一个有效作用靶点，且纹状体中的DAT功能是吗啡成瘾的一个指标。
