Fluorinated blood substitute retention in the rat measured by fluorine-19 magnetic resonance imaging.

Abstract

Emulsions of perfluorocarbons (PFCs) have been tested as blood substitutes. However, evidence exists that there is long-term retention of some PFCs by the organs of the reticuloendothelial system (RES). The authors investigate organ retention of the blood substitute component, perfluorotripropylamine (FTPA), using fluorine-19 (19F) magnetic resonance imaging (MRI). Various dosages of an emulsion of FTPA were administered to five rats. At intervals up to 86 weeks after infusion, 19F MRI was used to measure the amount of FTPA in liver and spleen. The data were fit to both linear and exponential elimination models, and organ retention half-lives were calculated. The exponential half-lives for combined liver and spleen FTPA ranged from 110 to 190 days. Linear half-lives ranged from 175 to 300 days. FTPA retained by the liver and spleen may be quantified by 19F MRI: The half-lives that were measured are longer than those reported previously for FTPA.