@article{oai:repo.qst.go.jp:00080946,
 author = {Okamura, Toshimitsu and Kikuchi, Tatsuya and Ming-Rong, Zhang and Okamura, Toshimitsu and Kikuchi, Tatsuya and Ming-Rong, Zhang},
 journal = {PET and SPECT of Neurobiological Systems},
 month = {Sep},
 note = {Multidrug resistance-associated protein 1 (MRP1) is a member of the adenosine triphosphate–binding cassette superfamily of transporters and plays an important role in limiting the permeation of xenobiotics and exporting endogenous substances across the blood-brain and blood-cerebrospinal fluid barriers, and across brain parenchymal cells in the central nervous system. In addition to multidrug resistance, changes in activity or expression of cerebral MRP1 occur in several brain diseases. Therefore, noninvasive and quantitative assessment of MRP1 activity in the brain is valuable for investigating the changes in MRP1 related to brain diseases, towards an understanding of the underlying molecular mechanisms. In this chapter, we will focus on 6-bromo-7-[11C]methylpurine for imaging MRP1 activity, as well as the concept of the metabolite extrusion method (MEM) for measuring efflux transporter activity. Several positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging studies of MRPs activity are also reviewed. Finally, we discuss our recent findings regarding the contribution of Mrp1 in brain parenchymal cells to tracer efflux, and the sensitivity of 6-bromo-7-[11C]methylpurine for measuring MRP1 activity.},
 title = {PET and SPECT of Neurobiological Systems},
 year = {2020}
}