“…Former studies have shown, that neither the removal of liver or spleen nor of the kidneys or the intestinal tract affects the elimination rates [38][39][40]42,56,57]. It was then believed that enzyme elimination might be a function of the reticule-endothelial system on the basis of indirect evidence before the era of labelled enzymes [37,42,44,58]. With 14C-acetylated LDH it was found that not the reticule-endothelial system but the parenchymal cells of most tissues are able to incorporate circulating enzyme molecules.…”