Propofol decreases in vivo binding of 11C-PBR28 to translocator protein (18 kDa) in the human brain

Christina S. Hines, Masahiro Fujita, Sami S. Zoghbi, Jin Su Kim, Zenaide Quezado, Peter Herscovitch, Ning Miao, Maria D. Ferraris Araneta, Cheryl Morse, Victor W. Pike, Julia Labovsky, Robert B. Innis

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

The PET radioligand 11C-PBR28 targets translocator protein (18 kDa) (TSPO) and is a potential marker of neuroimmune activation in vivo. Although several patient populations have been studied using 11C-PBR28, no investigators have studied cognitively impaired patients who would require anesthesia for the PET procedure, nor have any reports investigated the effects that anesthesia may have on radioligand uptake. The purpose of this study was to determine whether the anesthetic propofol alters brain uptake of 11C-PBR28 in healthy subjects. Methods: Ten healthy subjects (5 men; 5 women) each underwent 2 dynamic brain PET scans on the same day, first at baseline and then with intravenous propofol anesthesia. The subjects were injected with 680 ± 14 MBq (mean ± SD) of 11C-PBR28 for each PET scan. Brain uptake was measured as total distribution volume (VT) using the Logan plot and metabolite-corrected arterial input function. Results: Propofol decreased V T, which corrects for any alteration of metabolism of the radioligand, by about 26% (P = 0.011). In line with the decrease in V T, brain time-activity curves showed decreases of about 20% despite a 13% increase in plasma area under the curve with propofol. Reduction of V T with propofol was observed across all brain regions, with no significant region X condition interaction (P = 0.40). Conclusion: Propofol anesthesia reduces the VT of 11C-PBR28 by about 26% in the brains of healthy human subjects. Given this finding, future studies will measure neuroimmune activation in the brains of autistic volunteers and their age and sex-matched healthy controls using propofol anesthesia.We recommend that future PET studies using 11C-PBR28 and concomitant propofol anesthesia, as would be required in impaired populations, include a control arm to account for the effects of propofol on brain measurements of TSPO.

Original languageEnglish (US)
Pages (from-to)64-69
Number of pages6
JournalJournal of Nuclear Medicine
Volume54
Issue number1
DOIs
StatePublished - Jan 2013

Keywords

  • Anesthesia
  • Cognitive impairment
  • Neuroinflammation

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'Propofol decreases in vivo binding of <sup>11</sup>C-PBR28 to translocator protein (18 kDa) in the human brain'. Together they form a unique fingerprint.

Cite this