[A method for the study of relations between the lung and the reticulo-endothelial system]

The experiments reported in this paper draw attention to three new facts : 1) the reticulo-endothelial system (RES) of normal Rat can be " filled " with a non toxic, polymeric substance, PVNO, which is taken up by macrophages by pinocytosis ; 2) a broncho-pulmonary irritation leads to a discharge of PVNO by the macrophage. The macrophages are poured out into the blood stream, whence they arrive in to the lung ; 3) this discharge of a polymer as PVNO which has been previously taken in the macrophage, can happen even 10-12 months after the filling of the RES by the macromolecule.