Skip to Content
Merck
  • [11C]PBR28 PET imaging is sensitive to neuroinflammation in the aged rat.

[11C]PBR28 PET imaging is sensitive to neuroinflammation in the aged rat.

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism (2015-04-03)
Matthew D Walker, Katherine Dinelle, Rick Kornelsen, Nathan V Lee, Qing Miao, Mike Adam, Christine Takhar, Edwin Mak, Michael Schulzer, Matthew J Farrer, Vesna Sossi
ABSTRACT

Neuroinflammation in the aging rat brain was investigated using [(11)C]PBR28 microPET (positron emission tomography) imaging. Normal rats were studied alongside LRRK2 p.G2019S transgenic rats; this mutation increases the risk of Parkinson's disease in humans. Seventy [(11)C]PBR28 PET scans were acquired. Arterial blood sampling enabled tracer kinetic modeling and estimation of VT. In vitro autoradiography was also performed. PBR28 uptake increased with age, without differences between nontransgenic and transgenic rats. In 12 months of aging (4 to 16 months), standard uptake value (SUV) increased by 56% from 0.44 to 0.69 g/mL, whereas VT increased by 91% from 30 to 57 mL/cm(3). Standard uptake value and VT were strongly correlated (r = 0.52, 95% confidence interval (CI) = 0.31 to 0.69, n = 37). The plasma free fraction, fp, was 0.21 ± 0.03 (mean ± standard deviation, n = 53). In vitro binding increased by 19% in 16 months of aging (4 to 20 months). The SUV was less variable across rats than VT; coefficients of variation were 13% (n = 27) and 29% (n = 12). The intraclass correlation coefficient for SUV was 0.53, but was effectively zero for VT. These data show that [(11)C]PBR28 brain uptake increases with age, implying increased microglial activation in the aged brain.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Iodomethane, contains copper as stabilizer, ReagentPlus®, 99.5%
Sigma-Aldrich
Iodomethane, contains copper as stabilizer, ReagentPlus®, 99%
Sigma-Aldrich
N,N-Dimethylformamide, ACS reagent, ≥99.8%
Sigma-Aldrich
N,N-Dimethylformamide, anhydrous, 99.8%
Sigma-Aldrich
N,N-Dimethylformamide, for molecular biology, ≥99%
Sigma-Aldrich
Iodomethane, purum, ≥99.0% (GC)
Sigma-Aldrich
Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Sigma-Aldrich
Iodomethane-12C, ≥99.9 atom % 12C, ≥99% (CP), contains copper as stabilizer
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
N,N-Dimethylformamide, suitable for HPLC, ≥99.9%
Sigma-Aldrich
Iodomethane solution, 2.0 M in tert-butyl methyl ether, contains copper as stabilizer
Sigma-Aldrich
Acetonitrile, anhydrous, 99.8%
Sigma-Aldrich
Acetonitrile, ≥99.5%, ACS reagent
Sigma-Aldrich
Acetonitrile, HPLC Plus, ≥99.9%, poly-coated bottles
Sigma-Aldrich
Acetonitrile, electronic grade, 99.999% trace metals basis