Endoteelrakkud

Endoteelrakkud are the membrane‑bound cells that line the inner surface of blood vessels and lymphatic vessels. They form a contiguous monolayer called the endothelium, which serves as a selective barrier between the circulating blood and the surrounding tissues. Endoteelrakkud regulate vascular tone through the release of vasoactive substances such as nitric oxide, endothelin, and prostacyclin. They also mediate processes of angiogenesis, leukocyte adhesion, and hemostasis, and play a crucial role in immune surveillance by expressing adhesion molecules and cytokines.

Structurally, endoteelrakkud have a thin cytoplasm and a basal lamina beneath them. Their cell membrane is richly equipped with transport proteins, ion channels, and receptors that respond to mechanical shear stress, hormonal signals, and inflammatory mediators. The cells possess a specialized basal surface that contains fenestrations or a glycocalyx which permits the controlled movement of plasma proteins and other molecules.

Dysfunction of endoteelrakkud is implicated in a variety of cardiovascular diseases, including atherosclerosis, hypertension, and thrombosis. In diabetes, endothelial dysfunction can lead to microvascular complications such as retinopathy and nephropathy. Therapeutic strategies aimed at restoring endothelial health often involve lifestyle interventions, pharmacologic agents that improve nitric oxide bioavailability, and treatments targeting oxidative stress.

Scientific research on endoteelrakkud encompasses basic studies of endothelial biology, translational investigations into cardiovascular risk factors, and clinical trials evaluating agents that target endothelial cells. The term is commonly used in the Estonian language, and it directly translates to “endothelial cells” in English.