N-[11C-Methyl]chlorphentermine and N,N-[11C-dimethyl]chlorphentermine as brain blood-flow agents for positron emission tomography.
N-[11C-methyl]chlorphentermine ([11C]NMCP) and N,N-[11C-dimethyl]chlorphentermine ([11C]NDMCP) were prepared from chlorphentermine and 11CH3I in DMF and evaluated in rats as brain blood-flow agents for positron emission tomography (PET). Tissue distribution of [11C]NMCP showed that brain uptake was 2.70 +/- 0.40% of injected dose per organ at 5 min with no change in radioactivity concentration up to 30 min after i.v. injection. Approximately 80% of the initial brain uptake remained at 60 min. On the other hand, initial brain uptake of [11C] NDMCP (3.66 +/- 0.31 and 3.63 +/- 0.88% injected dose per organ at 5 and 15 min, respectively) was greater than that of [11C]NMCP. The brain activity however, rapidly decreased to 2.38 +/- 0.17 and 1.82 +/- 0.32% at 30 and 60 min, respectively. Because of its longer retention in the brain compared with [11C]NDMCP, [11C]NMCP would be a potential brain blood-flow agent for quantitative PET studies.
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging; D002250:Carbon Radioisotopes; D002560:Cerebrovascular Circulation; D002745:Chlorphentermine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D004341:Drug Evaluation; D010645:Phentermine / Q000031:analogs & derivatives*; D051381:Rats; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods*
D002250:Carbon Radioisotopes; C049343:N,N,-dimethylchlorphentermine; C049339:N-methylchlorphentermine; D010645:Phentermine; D002745:Chlorphentermine