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Event: 1673

Key Event Title

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

Alveolar collapse

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

Alveolar collapse

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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
Cellular

Cell 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

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; https://aopwiki.org/info_pages/2/info_linked_pages/7#List). 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

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
Lung surfactant function inhibition leading to decreased lung function	KeyEvent	Jorid Birkelund Sørli (send email)	Open for comment. Do not cite	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
human	Homo sapiens	High	NCBI
mouse	Mus musculus	High	NCBI
rat	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
Mixed	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

At the end of expiration, the alveoli are at their minimum volume, and the surface tension is at its lowest. If the surface tension is not sufficiently low at this point, the forces pulling the walls of the alveoli together during expiration cannot be overcome, and the alveoli might collapse (Notter and Wang 1997). Collapsed alveoli may however be re-opened by the force of air drawn into the lungs during inhalation. As breathing is continuous, the same alveoli can collapse and re-open repeatedly. The consequence of alveolar collapse can be observed as atelectasis upon histological examination, or can be indirectly inferred by reduced tidal volume or perfusion/ventilation mismatch (further details in the “Measurements of alveolar collapse” section).

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

There are approximately 480 million alveoli in the lungs (Ochs, Nyengaard et al. 2004). Alveolar collapse and re-opening can only happen in intact lungs in a living organism and thus cannot be measured in vitro. Further, because of their small diameter of approximately 200 µm in diameter (Ochs, Nyengaard et al. 2004), it is virtually impossible to measure the collapse and re-opening at the level of individual alveoli with any certainty. However, areas of atelectasis can be observed in experimental animals after staining of lung tissue from exposed animals (Jefferies, Kawano et al. 1988, Yamashita and Tanaka 1995, Nørgaard, Larsen et al. 2010).

Domain of Applicability

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

The applicability domain is restricted to the groups of organisms where the structure and the functioning of the pulmonary system, including the alveoli, are conserved and relevant.

References

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

Jefferies, A. L., T. Kawano, S. Mori and R. Burger (1988). "Effect of increased surface tension and assisted ventilation on 99mTc-DTPA clearance." J Appl Physiol (1985) 64(2): 562-568.

Notter, R. H. and Z. D. Wang (1997). "Pulmonary surfactant: Physical chemistry, physiology, and replacement." Reviews in Chemical Engineering 13(4): 1-118.

Nørgaard, A. W., S. T. Larsen, M. Hammer, S. S. Poulsen, K. A. Jensen, G. D. Nielsen and P. Wolkoff (2010). "Lung damage in mice after inhalation of nanofilm spray products: the role of perfluorination and free hydroxyl groups." Toxicol Sci 116(1): 216-224.

Ochs, M., J. R. Nyengaard, A. Jung, L. Knudsen, M. Voigt, T. Wahlers, J. Richter and H. J. Gundersen (2004). "The number of alveoli in the human lung." Am J Respir Crit Care Med 169(1): 120-124.

Yamashita, M. and J. Tanaka (1995). "Pulmonary Collapse and Pneumonia Due to Inhalation of a Waterproofing Aerosol in Female Cd-1 Mice." Journal of Toxicology-Clinical Toxicology 33(6): 631-637.