Abstract
Cocaine analogs such as 3β‐(4‐iodophenyl)tropane‐2β‐carboxylic acid methyl ester (RTI‐55 or βCIT) with a higher affinity for the dopamine transporter (DAT) may be potentially useful in interfering with cocaine's actions in brain. This study evaluates the time course of the effects of RTI‐55 on cocaine binding in baboon brain using PET and [11C]cocaine. [11C]Cocaine binding was measured prior to, and 90 minutes, 24 hours, 4–5 days and 11–13 days after RTI‐55 (0.3 mg/kg i.v.). Parallel studies with [3H]cocaine and RTI‐55 (0.5 mg/kg i.v. or 2 mg/kg i.p.) were performed in the mouse. RTI‐55 significalitly inhibited [11C]cocaine binding at 90 minutes and 24 hours after administration.The half‐life for the clearance of RTI‐55 from the DAT was estimated to be 2 to 3 days in the baboon brain. In the mouse brain, RTI‐55 significantly inhibited [3H]cocaine binding at 60 and 180 minutes after administration and recovery was observed at 12 hours. These results document long‐lasting inhibition of cocaine binding by RTI‐55 and corroborate that binding kinetics of RTI‐55 in striatum observed in imaging studies with [123I]RTI‐55 represents binding to DATs. © 1995 Wiley‐Liss, Inc.
Original language | English |
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Pages (from-to) | 206-211 |
Number of pages | 6 |
Journal | Synapse |
Volume | 19 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1995 |
Externally published | Yes |
Keywords
- Baboon
- Carbon‐11
- PET