Importantly, both [11C]MPDX or [18F]CPFPX are inverse agonist of the A1R. [11C]MPDX did not compete with either endogenous or exogenous agonist in receptor binding but did show an increased binding potential without enhanced tracer delivery to the brain.88 Despite stated limitations, these tracers85 have presented promising imaging tools for mapping of A1R in the brain86,87,96. A list of all aforementioned A1R PET radioligands is presented in Table 1.
