The pathological relevance of increased endothelial glycocalyx permeability

Abstract The endothelial glycocalyx is a vital regulator of vascular permeability. Damage to this delicate layer can result in increased protein and water transit. The clinical importance of albuminuria as a predictor of kidney disease progression and vascular disease has driven research in this area. This review outlines how research to date has attempted to measure the contribution of the endothelial glycocalyx to vessel wall permeability. We discuss the evidence for the role of the endothelial glycocalyx in regulating permeability in discrete areas of the vasculature and highlight the inherent limitations of the data that has been produced to date are highlighted. In particular, this review draws the reader’s attention to the difficulties in interpreting urinary albumin levels in early disease models. In addition, the research supporting the view that glycocalyx damage is a key pathological step in a diverse array of clinical conditions including diabetic complications, sepsis, preeclampsia and atherosclerosis is summarized. Finally, novel methodologies are discussed including an ex vivo glomerular permeability assay that enhances the understanding of permeability changes in disease.