| Autor: |
Del Rosario RB; Division of Nuclear Medicine, University of Michigan Medical Center, Ann Arbor 48109-0552, USA., Jung YW, Caraher J, Chakraborty PK, Wieland DM |
| Jazyk: |
angličtina |
| Zdroj: |
Nuclear medicine and biology [Nucl Med Biol] 1996 Jul; Vol. 23 (5), pp. 611-6. |
| DOI: |
10.1016/0969-8051(96)00057-1 |
| Abstrakt: |
The in vivo behavior of (-)-[11C]phenylephrine (PHEN) is compared with the structurally similar but monoamine oxidase (MAO)-resistant analog (-)-[11C]-m-hydroxyephedrine (HED), which is an established heart neuronal marker. The chiral synthesis of PHEN has been achieved by direct methylation of (-)-m-octopamine with either 11CH3I or CF3SO311CH3. These synthetic methods produced PHEN with a specific activity ranging from 500-1000 Ci/mmol, in a radiochemical yield of > 50% (EOS) and with an enantiomeric purity of 94-96%. Biodistribution studies indicate the initial uptake of PHEN in rat heart is approximately half that of HED. Following PHEN injection, radioactivity egresses from the rat heart rapidly, with 50% washout occurring from 5 to 60 min. HED washout over this interval was less than 20%. The heart neuronal selectivity determined by desipramine blockade of the amine neuronal transporter was 75-77% compared to 92-95% for HED. Ring-labeled (-)-[3H]phenylephrine gave tissue-to-blood concentration ratios and heart clearance times very similar to PHEN. Rats pretreated with the MAO A inhibitor clorgyline showed higher levels of activity in the heart at 15 and 60 min. Tandem PET studies with PHEN and HED in the closed-chest dog provided excellent heart images with both tracers. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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