This chapter discusses the studies of interstitial fluid lipoproteins and their metabolism may provide the important link between tissue culture studies and in vivo studies of plasma lipoprotein metabolism. Perinodal peripheral lymph is an accepted model of interstitial fluid. The chapter also presents techniques, which allow collection of perinodal peripheral lymph in quantities sufficient for analytical or metabolic studies of interstitial fluid. The dog as an experimental model offers advantages in ease of surgical procedures, quantities of fluid obtained, and a well-characterized plasma lipoprotein profile. The experimental designs and data presented are examples of the potentially important information that can be obtained from studies of peripheral (or deep muscle) lymph lipoproteins. The chapter provides a link between studies on plasma lipoprotein metabolism and tissue culture studies using peripheral cell cultures (such as macrophage, smooth muscle cells, or endothelial cells) and thus provide an important contribution to the understanding of the function of lipoproteins.