Changes of dopamine transporter function in striatum during acute morphine addiction and its abstinence in rhesus monkey.
- Author:
Zhuang-wei XIAO
1
;
Chu-yu CAO
;
Zhao-xin WANG
;
Jun-xiong LI
;
Hai-yong LIAO
;
Xue-xin ZHANG
Author Information
- Publication Type:Journal Article
- MeSH: Acute Disease; Animals; Cerebellum; metabolism; Corpus Striatum; drug effects; metabolism; Dopamine Plasma Membrane Transport Proteins; analysis; physiology; Female; Macaca mulatta; Male; Morphine Dependence; physiopathology; Organotechnetium Compounds; Tomography, Emission-Computed, Single-Photon; Tropanes
- From: Chinese Medical Journal 2006;119(21):1802-1807
- CountryChina
- Language:English
-
Abstract:
BACKGROUNDAlthough 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.
METHODSFour 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.
RESULTSThe 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.
CONCLUSIONSIn 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.
