Background 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 dopam...Background 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. Methods 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 ^99Tc^m-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. Results 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. Conclusions In rhesus monkey, acute morphine injection has both rapid and lasting effects on DAT by downregnlating 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.展开更多
基金This research was supported by grants from the National Natural Science Foundation of China (No. 30420120048 and No. 30200068), the Fok Ying Tung Education Foundation (No. 91038) and the Famous Doctor Project of the Department of Health of Guangdong Province (No. 21).
文摘Background 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. Methods 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 ^99Tc^m-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. Results 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. Conclusions In rhesus monkey, acute morphine injection has both rapid and lasting effects on DAT by downregnlating 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.
