Endotelbarriären

Endotelbarriären, often referred to as the endothelial barrier, is a crucial interface within the circulatory system. It is formed by a single layer of endothelial cells that line the inner surface of all blood vessels, from large arteries to tiny capillaries. This barrier plays a vital role in regulating the passage of substances between the bloodstream and the surrounding tissues. Its primary function is to maintain homeostasis, ensuring that essential nutrients and oxygen reach cells while simultaneously preventing the entry of harmful pathogens and toxins into the circulation.

The integrity of the endotelbarriär is maintained through a complex interplay of cellular junctions, including tight junctions and adherens junctions, which act as seals between endothelial cells. These junctions are dynamic and can be modulated by various physiological and pathological stimuli. The barrier is not entirely impermeable; it possesses selective permeability, allowing for the controlled transport of specific molecules through processes such as transcytosis and paracellular diffusion.

Dysfunction of the endotelbarriär is implicated in a wide range of diseases. Increased permeability, often termed "leaky" endothelium, can lead to inflammation, edema, and the exacerbation of conditions like sepsis, atherosclerosis, and autoimmune disorders. Conversely, excessive barrier tightening can impair nutrient and oxygen delivery. Research into the endotelbarriär is ongoing, seeking to understand its intricate mechanisms and develop therapeutic strategies to restore its proper function in disease states.