Perfluorochemical perfusion of the rat heart: in vivo and in vitro

Abstract

Perfluorochemical (PFC) perfusates were evaluated in this study for inherent differences obtained by perfusion in vivo and of the heart in vitro. The sources of the PFC's were commercial products: Fluosol DA 20%, Fluosol DA 35%, and Fluosol-43. The first two contain both perfluorodecalin (PD) and perfluorotripropylamine (PTPA), while the third utilizes only perfluorotributylamine (PTBA). The hearts studied were excised from control animals or from animals that were first exchange perfused in vivo with Fluosol-43. For studies in vitro hearts perfused in the presence of PTBA beat at a normal rate for 10 to 12 h and then gradually slowed. By comparison, hearts perfused with Krebs-Henseleit solution (KHS) or PD-PTPA containing perfusates maintained a normal heart rate only briefly and ceased beating within 5 to 10 h. However, excised hearts from animals perfused previously in vivo with the PD-PTPA (35%) mixture showed an initial increase followed by a rapid drop in cAMP and cGMP concentrations of the left ventricle. When the other two PFC-containing perfusates were used, no significant changes were found. Only the PTBA-containing mixture maintained normal levels of the two nucleotides and Na +, K + and Ca 2+ levels of the left ventricle in vitro. Also, for studies in vitro when linoleic (0.156 μ m) and palmitic (0.086 μ m) acids were added simultaneously to all PFC preparations the PTBA-containing perfusate maintained a normal heart rate for over 10 h. Beating hearts were maintained most effectively when hydroxyethylstarch, an oncotic component, was present at 3% (w/v). These studies demonstrate that suitable PFC-containing perfusates can maintain beating rat hearts for many hours at 37°C.