THE DISTRIBUTION OF [C-11] COCAINE IN NORMAL AND COCAINE-SENSITIZATION MICE

[N-C-11-methyl]-cocaine ([C-11]cocaine), synthesized by N-methylation of norcocaine with [C-11]CH3I, was used to assist in imaging the varie ty of local distribution by positron emission tomography (PET). The ra diochemical yield and the radiochemical purity after purification of [ C-11]cocaine by high performance liquid chromatography (HPLC) at a sp. act. of 814 GBq/mmol were 47-58% and >99%, respectively. The time req uired for synthesis including the purification was 25-30 min from the end of [C-11]CH3I trapping. The physical distribution of [C-11]cocaine in organ was also investigated in mice at various time after i.v. inj ection. The main accumulation of radioactivity occurred in the lung, k idney and brain within 1 min after the injection. In the brain, no dif ferences in the organ were observed except the radioactivity level in each section increased for the first 5 min, since then radioactivity d ecreased dramatically. Furthermore, in the behavioral sensitization mo del of cocaine, the peak of [C-11]cocaine uptake in each brain area wa s shown to be 5-15 min.