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Event: 937

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

KE7 : Impaired, Vasodilation

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Impaired, Vasodilation
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Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. More help
Level of Biological Organization

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Organ term
circulatory system

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Process Object Action
vasodilation blood vessel abnormal

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE. Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
Hypertension KeyEvent Frazer Lowe (send email) Not under active development Under Development

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
Homo sapiens Homo sapiens High NCBI
Oryctolagus cuniculus Oryctolagus cuniculus Low NCBI
Mus musculus Mus musculus Moderate NCBI
Rattus norvegicus Rattus norvegicus Moderate NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help
Life stage Evidence
All life stages High

Sex Applicability

An indication of the the relevant sex for this KE. More help
Term Evidence
Unspecific High

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

Vasodilation refers to the widening or increase in the diameter of blood vessels (e.g. large arteries, large veins, small arterioles) that is caused by the relaxation of vascular smooth muscle cells (VSMCs) within the walls of blood vessels, thus increasing blood flow and decreasing arterial blood pressure and heart rate (Siddiqui, 2011). VSMC relaxation is regulated through a number of mechanisms, including cyclic GMP-dependent hyperpolarization and relaxation via nitric oxide (NO), cAMP-dependent hyperpolarization via prostaglandins, and stimulation of potassium channels via endothelial-derived hyperpolarizing factors (Durand and Gutterman, 2013). Under oxidative stress, decreased NO bioavailability results in impaired vasodilation, which is associated with cardiovascular diseases such as hypertension (Silva et al., 2012).

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

Endothelium-dependent vasodilation can be measured using invasive and non-invasive methods (Raitakari and Celermajer, 2000). For the invasive approach, vasodilation is measured after intra-arterial pharmacologic stimulation with substances that enhance NO release (e.g. acetylcholine, bradykinin). The non-invasive ultrasound-based method evaluates flow-mediated vasodilation (FMD) in the superficial arteries, such as brachial, radial, or femoral vessels.

Guidelines for the measurement of FMD have been published (Corretti et al. 2002).

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help

Vasodilation has been observed in humans, rabbits, mice and rats.


List of the literature that was cited for this KE description. More help

Guidelines for the ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery

Corretti MC, Anderson TJ, Benjamin EJ, Celermajer D, Charbonneau F, Creager MA, Deanfield J, Drexler H, Gerhard-Herman M, Herrington D, Vallance P, Vita J, Vogel R.  Guidelines for the ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery.  Journal of the American College of Cardiology, 2002, 39 (2) 257-265

Durand, M.J., and Gutterman, D.D. (2013). Diversity in mechanisms of endothelium-dependent vasodilation in health and disease. Microcirc. N. Y. N 1994 20, 239–247.

Raitakari, O.T., and Celermajer, D.S. (2000). Flow-mediated dilatation. Br. J. Clin. Pharmacol. 50, 397–404.

Siddiqui, A. (2011). Effects of Vasodilation and Arterial Resistance on Cardiac Output. J. Clin. Exp. Cardiol. 02.

Silva, B.R., Pernomian, L., and Bendhack, L.M. (2012). Contribution of oxidative stress to endothelial dysfunction in hypertension. Front. Physiol. 3, 441.