% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@INPROCEEDINGS{Michno:1027709,
      author       = {Michno, M. and Weis, H. and Schmitz, J. and Foerges, Anna
                      Linea and Beer, Simone and Neumaier, B. and Drzezga, A. and
                      Aeschbach, D. and Bauer, Andreas and Tank, J. and
                      Elmenhorst, E. and Elmenhorst, D.},
      title        = {{E}ffect of acute hypoxia exposure on the availability of
                      {A}1 adenosine receptors in the human brain measured with
                      [{F}-18]{CPFPX} {PET}},
      reportid     = {FZJ-2024-04019},
      year         = {2023},
      abstract     = {Ziel/Aim Normobaric hypoxia induces numerous adaptive
                      changes, e. g., incerebral blood flow, metabolism and
                      electrical activity. Adenosine, as an
                      inhibitoryneuromodulator, is produced in and/or released to
                      the interstitial spaceduring hypoxia and assumed to mediate
                      several of these effects. A1 adenosinereceptor (A1AR)
                      antagonism or knock-out attenuates this neuronal
                      inhibitionin mice. Here we tested the hypothesis that
                      exposure to an interval of hypoxiacompared to an interval of
                      normoxia (control) reduces the availability of A1ARin the
                      human brain, due to hypoxia-triggered rise of endogenous
                      adenosine.As exploratory objectives, we tested the
                      hypotheses that psychomotor vigilanceis affected during
                      hypoxia and that cerebral blood flow is
                      altered.Methodik/Methods Ten healthy volunteers (32 ± 13
                      years, 3f) completed an110-min bolus plus constant infusion
                      [F-18]CPFPX PET-MRI hybrid experiment:Subjects spent the
                      first 60 minutes of the scan in normoxia followed by
                      30minutes of individually adapted normobaric hypoxia to
                      achieve a peripheraloxygen saturation of 70 - 75 $\%,$
                      followed by 20 minutes of normoxia. Bloodsamples were used
                      to calculate metabolite-corrected steady-state
                      distributionvolumes (VT) of A1AR (i. e., 40 – 100 min
                      after start of [F-18]CPFPX administration).Brain perfusion
                      was measured via arterial spin labelling. A
                      3-minutepsychomotor vigilance test (PVT) was conducted every
                      10 minutes. Heart rateand peripheral blood oxygen saturation
                      were measured continuously.Ergebnisse/Results Hypoxia
                      reduced A1AR availability in the cerebral cortexby 11 $\%$
                      (p = 0.033). Compared to normoxia, brain perfusion increased
                      duringhypoxia by 25 $\%$ in cortical gray matter (p <
                      0.001). Heart rate increased by 22 $\%(p$ < 0.001). PVT mean
                      reaction time was longer by 7 ms (p =
                      0.027).Schlussfolgerungen/Conclusions Short term reduction
                      of the oxygen saturationto 70 $\%$ (corresponding to an
                      oxygen saturation at an altitude of approximately6000 m)
                      increases cerebral blood flow and impairs cognitive
                      performancewhile A1AR availability is reduced. This
                      indicates that acute hypoxiaexposure increases cerebral
                      adenosine concentration and receptor occupancy.},
      month         = {Apr},
      date          = {2023-04-19},
      organization  = {61. Jahrestagung der Deutschen
                       Gesellschaft für Nuklearmedizin,
                       Leipzig (Germany), 19 Apr 2023 - 22 Apr
                       2023},
      subtyp        = {After Call},
      cin          = {INM-5},
      cid          = {I:(DE-Juel1)INM-5-20090406},
      pnm          = {5253 - Neuroimaging (POF4-525)},
      pid          = {G:(DE-HGF)POF4-5253},
      typ          = {PUB:(DE-HGF)6},
      doi          = {10.1055/s-0043-1766157},
      url          = {https://juser.fz-juelich.de/record/1027709},
}