The endothelial glycocalyx and its disruption, protection and regeneration: a narrative review

Abstract

The glycocalyx is a carbohydrate-rich layer that lines the luminal side of the vascular endothelium. Its soluble components exist in a dynamic equilibrium with the bloodstream and play an important role in maintaining endothelial layer integrity. However, the glycocalyx can be easily damaged and is extremely vulnerable to insults from a variety of sources, including inflammation, trauma, haemorrhagic shock, hypovolemia and ischaemia-reperfusion. Damage to the glycocalyx commonly precedes further damage to the vascular endothelium. Preclinical research has identified a number of different factors capable of protecting or regenerating the glycocalyx. Initial investigations suggest that plasma may convey protective and regenerative effects. However, it remains unclear which exact components or properties of plasma are responsible for this protective effect. Studies have reported protective effects for several plasma proteins individually, including antithrombin, orosomucoid and albumin; the latter of which may be of particular interest, due to the high levels of albumin present in plasma. A further possibility is that plasma is simply a better intravascular volume expander than other resuscitation fluids. It has also been proposed that the protective effects are mediated indirectly via plasma resuscitation-induced changes in gene expression. Further work is needed to determine the importance of specific plasma proteins or other factors for glycocalyx protection, particularly in a clinical setting.

Direct Observation of Enhanced Nitric Oxide in a Murine Model of Diabetic Nephropathy

“…In diabetes, various factors can lead to disruption of the glycocalyx [29]. Heparanase-mediated degradation of heparan sulphate represents one of the most widely recognized causes of glycocalyx perturbation.…”

Recent advances in the understanding of endothelial barrier function and fluid therapy

“…It has been found to be rather delicate and can be disrupted by several pathophysiological pathways 16. Also, chemical interaction is as important as size in determining glycocalyx permeability to solutes 15.…”

Baixas doses de hidrocortisona possuem ação protetora no choque hemorrágico em ratos

“…Após essa estimulação, inicia-se uma cascata molecular culminando na secreção de citocinas efetoras, tais como TNF-α e IL-6 11,12 . Já foi demonstrado que baixas doses de hidrocortisona, apresentam efeito protetor sobre o endotélio vascular no momento da reperfusão sanguínea por um mecanismo de estabilização de membranas e da microcirculação, diminuindo a inflamação pela inibição da liberação de citocinas pró-inflamatórias, principalmente no sistema nervoso central e do trato gastrointestinal [13][14][15][16] . Além disso, o uso de baixas doses de hidrocortisona sensibiliza o organismo aos efeitos de catecolaminas, ajuda na melhora da pressão arterial e uma reanimação mais rápida 13,15,17 .…”