Importance of endothelial function
- Created by: milliehubbard1
- Created on: 19-04-17 11:19
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- Importance of endothelial function
- Arteries: conduit (elastic), muscular (distributing)
- ACh: vasorelaxant
- EDRF: endothelium derived relaxant factor
- Stimlulus for basal release is flow. Cell surface senses shear stress > intracellular signalling events > release
- Shown to be NO
- NO production: agonist stimulated
- Secreted by endothelium
- Enzyme: eNOS, Precursor: L-arginine, Co-factor: BH4
- Activation of eNOS follows a rise in intracellular calcium
- NO increases production of cGMP, which reverses vasoconstriction
- NO decreases: SM contraction, platelet aggrevation, LDL oxidation, expression of adhesion molecules, platelet adhesion
- Gap junction dependent
- Function of endothelium: Regulation of: haemostasis, angiogenesis, permeability, inflammation, vascular tone, synthesis and release of factors
- LDL undergoes oxidative modification with intima and becomes ox LDL
- Develops at arterial branches and sites of curvature / bifurcation: regions of low and disturbed wall shear stress
- Disturbed flow leads to decrease in: eNOS production, vasodilation, endothelial cell repair
- Develops at arterial branches and sites of curvature / bifurcation: regions of low and disturbed wall shear stress
- Endothelium: monolayer forming lumen of all blood vessels
- Releases vasoactive agents that control functions e.g tone and haemostasis
- Dysfunction: looses tightly regulated balance > vasospasm and atherosclerosis > CHD, hypertension, stroke
- Oxidative stress reduces effects / bioavailability of NO.. May produce superoxide O2-, producing peroxynitrate ONOO-
- Peroxynitrate interacts with lipids, DNA and proteins
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