Comparison of two I-123 labeled SPECT probes, for the dopamine transporter in non-human primate brain
- Yale Univ., West Haven, CT (United States); and others
A comparative SPECT evaluation of the regional uptake of 28-carboisopropoxy-3{beta}-(4-iodophenyl)tropane (IP-CIT) and 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ({beta}-CIT) was performed to assess the improved specificity of IP-CIT over {beta}-CIT for the dopamine (DE) transporter, as shown previously by in vitro studies (n=10), ranging from 7 to 10 hours with 6.9 to 15 mCi injected dose, were completed in 3 baboons. Peripheral metabolism of the two ligands were similar The SPECT images utilized ROIs over striatum (which reflect DA transporters), midbrain (previously shown for {beta}-CIT to reflect primarily serotonin transporters), and the occipital lobe (a region of non-specific uptake). The time to peak specific striatal uptake (striatal minus occipital activity) was similar for IP-CIT and {beta}-CIT (377{plus_minus}60 and 410{plus_minus}60 min, respectively); whereas midbrain peak activity occurred at a significantly earlier time for IP-CIT (21{plus_minus}4 min) as compared to {beta}-CIT (60{plus_minus}17 min). At time of peak specific striatal activity, striatal to occipital ratios were 2.7+0.6 for IP-CIT and 7.6{plus_minus}0.7 for {beta}-CIT, and at time of peak midbrain activity, midbrain to occipital ratios were 1.1{plus_minus}0.1 for IP-CIT, and 1.7{plus_minus}0.2 for {beta}-CIT. At peak specific striatal time, normalized regional uptake values ({mu}Ci/cc per {mu}Ci injected dose per g body mass) for the striatum were 4.9{plus_minus}1.1 IP-CIT and 5.2{plus_minus}0.7 {beta}-CIT, whereas for the occipital lobe normalized regional uptake values were 1.9{plus_minus}0.4 IP-CIT and 0.7{plus_minus}0.2 for {beta}-CIT. Similar regional kinetics in the striatum were observed, as both ligands demonstrate comparable peak striatal uptake and time to peak.
- OSTI ID:
- 198050
- Report Number(s):
- CONF-940605-; ISSN 0161-5505; TRN: 95:007029-0198
- Journal Information:
- Journal of Nuclear Medicine, Vol. 35, Issue Suppl.5; Conference: 41. annual meeting of the Society of Nuclear Medicine, Orlando, FL (United States), 5-8 Jun 1994; Other Information: PBD: May 1994
- Country of Publication:
- United States
- Language:
- English
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