Skip to main content
. Author manuscript; available in PMC: 2012 Aug 1.
Published in final edited form as: Nucl Med Biol. 2011 May 5;38(6):771–780. doi: 10.1016/j.nucmedbio.2011.02.002

Figure 1. Chemical compartment schematic of the Cu-ATSM and FMISO retention mechanisms in hypoxic tumor cells.

Figure 1

The free tracer passively diffuses into cells and is reduced either by specific microsomal cytochrome reductases (CR) or more indiscriminate mitochondrial nitroreductases (NR) in the redox compartment. The reduced tracer is preferentially reoxidized by molecular oxygen in normoxic cells, while under hypoxic conditions it is protonated (Cu-ATSM) or further reduced (FMISO) in the bound compartment. Cu-ASTM is dissociated by reactive chemical species (RSH), while FMISO aliphatic and ring labels bind to intracellular macromolecules [15–16,26,30].