COMPARISON OF 3 COMMERCIAL PERFLUOROCARBON EMULSIONS AS HIGH-FIELD F-19 NMR PROBES OF OXYGEN-TENSION AND TEMPERATURE

The increasing use of perfluorocarbons (PFCs) as probes of tissue oxyg enation on the basis of the F-19 spin-lattice relaxation rate (R(1)) p rompts comparison between several commercially available PFC blood-sub stitute emulsions, The relative sensitivities to both oxygen and tempe rature of the emulsions Oxypherol, Oxygent, and Fluosol at 7 T have be en investigated, The linear response of R(1) with pO(2) was confirmed for each resonance in the range 4-50 degrees C, In general, R(1) is no t a linear function of temperature, and we demonstrate this for perflu orotributylamine (FTBA) over an extended range of temperatures, 239-34 3 K. Theoretical R(1) values of FTBA were compared with experimental d ata by computer modeling of relaxation mechanisms, To further understa nd the structure-function relationships of PFCs, 2D COSY experiments w ere used for the assignment of resonances and as an aid in interpretat ion of relaxation mechanisms, Finally, the utility of Oxygent and Oxyp herol for measuring tissue pO(2) in perfused rat hearts was compared b efore, during, and after eight minutes of global ischemia. (C) 1995 Ac ademic Press, Inc.