Fig. 1Routes of transendothelial transport. A schematic representation of paracellular and transcellular routes for transport of blood-borne hormones and solutes to interstitial space of underlying tissue.
Fig. 2Diversity of paracellular transport characteristics in different vascular beds. The size and structure of tight junctions varies significantly between different tissues and in this figure we summarize this by defining three arbitrary categories of leaky, moderately tight and tight endothelia. The typical resistance values associated with these definitions and examples of tissues where each category of endothelium is characteristic is shown. N/A, not applicable.
Fig. 3Paracellular movement of adiponectin. A conceptual model showing the potential significance of paracellular transendothelial movement of adiponectin. When vascular endothelium is leaky (left side) there is significant flux of all forms of adiponectin from bloodstream to interstitial space. However, as endothelium becomes tighter there is likely to be a gradient of decrease in high molecular weight or other multimeric forms of adiponectin whereas the smaller globular fragment of adiponectin may still be able to access underlying target tissue such as skeletal muscle. TJ, tight junctions; fAd, full length adiponectin; gAd, globular adiponectin.