Discussion and Considerations for the Excretion Mechanism of Perfluorochemical Emulsion

Abstract

It has been assumed that a mononuclear phagocyte system is related to the excretion of PFC emulsions: PFC particles are phagocytized by blood monocytes to be expelled through the lung alveoli. This monocyte-related mechanism may well explain excretion at an early stage when PFC particles are abundant in the blood stream. It does not, however, fully explain the manner by which PFC cells are released from the RES cells into the blood stream and into the adipose tissue. To explain this, the following mechanism has been proposed and discussed based on some experimental results. PFC emulsion particles taken up by the RES organs, are stripped at their surfactant layers in the cells and move across the cell membranes to the blood vessels and into other tissues such as adipose, at a rate that depends on the lipophilicity of the PFC's. In the blood stream, PFCs are delivered by lipoproteins to the lung and excreted into the expired air. Pharmacokinetical analysis with a compartmental model for the excretion also supported this proposed mechanism.