Editing Endothelial dysfunction (section)

{{Short description|Impaired function of the inner lining of blood/lymph vessels}}
{{more medical citations needed|date=April 2018}}
{{Technical|date=February 2022}}
[[File:Viruses-13-00029-g001.webp|thumb|Comparison of healthy vs. dysfunctional vascular endothelium]]

In [[vascular disease]]s, '''endothelial dysfunction''' is a systemic pathological state of the [[endothelium]]. The main cause of endothelial dysfunction is impaired bioavailability of [[nitric oxide]].<ref name="pmid31354915">{{cite journal | vauthors = Marchio P, Guerra-Ojeda S, Mauricio MD | title=Targeting Early Atherosclerosis: A Focus on Oxidative Stress and Inflammation | journal= [[List of Hindawi academic journals#O|Oxidative Medicine and Cellular Longevity]] | volume=2019 | pages=8563845 | year=2019 | doi= 10.1155/2019/8563845 | pmc=6636482 | pmid=31354915 | doi-access=free }}</ref>

In addition to acting as a [[semipermeable membrane]], the endothelium is responsible for maintaining [[vascular tone]] and regulating [[oxidative stress]] by releasing mediators, such as nitric oxide, [[prostacyclin]] and [[endothelin]], and by controlling local [[angiotensin]]-II activity.<ref>{{Cite journal|last1=Sitia|first1=S.|last2=Tomasoni|first2=L.|last3=Atzeni|first3=F.|last4=Ambrosio|first4=G.|last5=Cordiano|first5=C.|last6=Catapano|first6=A.|last7=Tramontana|first7=S.|last8=Perticone|first8=F.|last9=Naccarato|first9=P.|title=From endothelial dysfunction to atherosclerosis|journal=Autoimmunity Reviews|volume=9|issue=12|pages=830–834|doi=10.1016/j.autrev.2010.07.016|pmid=20678595|year=2010}}</ref><ref>{{cite journal |vauthors=Flammer AJ, Anderson T, Celermajer DS, Creager MA, Deanfield J, Ganz P, Hamburg NM, Lüscher TF, Shechter M, Taddei S, Vita JA, Lerman A | date = Aug 2012 | title = The assessment of endothelial function: from research into clinical practice | journal = Circulation | volume = 126 | issue = 6| pages = 753–67 | doi=10.1161/circulationaha.112.093245| pmid = 22869857 | pmc = 3427943 }}</ref>

Dysfunctional endothelium is characterized by [[vasoconstriction]], increased [[vascular permeability]], [[thrombosis]], and [[inflammation]]. This pathological state is often associated with elevated levels of [[biomarker]]s such as [[prothrombin time]], [[D-dimer]], [[von Willebrand factor]], [[fibrin degradation product]]s, [[C-reactive protein]] (CRP), [[ferritin]], [[Interleukin 6]] (IL-6), and plasma [[creatinine]]. The result of this endothelial dysregulation is a cascade of adverse effects, including vasoconstriction, [[Capillary leak syndrome|vascular leakage]], thrombosis, hyperinflammation, and a disrupted antiviral [[immune response]]. These changes contribute to the progression of vascular diseases.<ref name=":0">{{Cite journal |last1=Bernard |first1=Isabelle |last2=Limonta |first2=Daniel |last3=Mahal |first3=Lara K. |last4=Hobman |first4=Tom C. |date=January 2021 |title=Endothelium Infection and Dysregulation by SARS-CoV-2: Evidence and Caveats in COVID-19 |journal=Viruses |language=en |volume=13 |issue=1 |pages=29 |doi=10.3390/v13010029 |pmid=33375371 |pmc=7823949 |issn=1999-4915 |doi-access=free }}</ref>

In a healthy state, the endothelium exhibits [[vasodilation]], tightly controlled vascular permeability, and anti-thrombotic and anti-inflammatory properties. This balance ensures the smooth functioning of the vascular system.<ref name=":0" />