Kinetic modeling of the monoamine oxidase B radioligand [¹¹C]SL25.1188 in human brain with high-resolution positron emission tomography

J Cereb Blood Flow Metab. 2014 May;34(5):883-9. doi: 10.1038/jcbfm.2014.34. Epub 2014 Feb 12.

Abstract

This article describes the kinetic modeling of [(11)C]SL25.1188 ([(S)-5-methoxymethyl-3-[6-(4,4,4-trifluorobutoxy)-benzo[d]isoxazol-3-yl]-oxazolidin-2-[(11)C]one]) binding to monoamine oxidase B (MAO-B) in the human brain using high-resolution positron emission tomography (PET). Seven healthy subjects underwent two separate 90- minute PET scans after an intravenous injection of [(11)C]SL25.1188. Complementary arterial blood sampling was acquired. Radioactivity was quickly eliminated from plasma with 80% of parent compound remaining at 90 minutes. Metabolites were more polar than the parent compound. Time-activity curves showed high brain uptake, early peak and washout rate consistent with known regional MAO-B concentration. A two-tissue compartment model (2-TCM) provided better fits to the data than a 1-TCM. Measurement of total distribution volume (VT) showed very good identifiability (based on coefficient of variation (COV)) for all regions of interest (ROIs) (COV(VT)<8%), low between-subject variability (∼20%), and quick temporal convergence (within 5% of final value at 45 minutes). Logan graphical method produces very good estimation of VT. Regional VT highly correlated with previous postmortem report of MAO-B level (r(2)= ≥ 0.9). Specific binding would account from 70% to 90% of VT. Hence, VT measurement of [(11)C]SL25.1(1)88 PET is an excellent estimation of MAO-B concentration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Brain / diagnostic imaging*
  • Brain / enzymology*
  • Carbon Radioisotopes / chemistry
  • Carbon Radioisotopes / metabolism*
  • Female
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Monoamine Oxidase / analysis*
  • Monoamine Oxidase / metabolism
  • Oxazolidinones / chemistry
  • Oxazolidinones / metabolism*
  • Positron-Emission Tomography
  • Protein Binding
  • Rats
  • Rats, Sprague-Dawley
  • Young Adult

Substances

  • Carbon Radioisotopes
  • Oxazolidinones
  • Monoamine Oxidase