Application of carbon monoxide diffusing capacity in the mouse lung.

Area of Science:

• Pulmonary Physiology
• Animal Models of Lung Disease
• Respiratory Medicine

Background:

• Mice are crucial models for studying lung diseases, necessitating reliable functional measurements.
• Assessing lung pathology requires methods that reflect structural changes, like diffusing capacity for carbon monoxide (DL(CO)).
• Previous DL(CO) measurements in mice faced technical challenges, limiting widespread use.

Purpose of the Study:

• To develop a simplified, reproducible method for measuring lung diffusion in mice.
• To introduce a dimensionless variable, the diffusion factor for carbon monoxide (DF(CO)), closely related to DL(CO).
• To validate the DF(CO) method in common mouse models of lung pathology.

Main Methods:

• A 9-second lung inflation with tracer gases in anesthetized mice.
• A subsequent 1-minute gas analysis period.
• Testing the DF(CO) method in elastase-induced emphysema and bleomycin-induced fibrosis models.

Main Results:

• The DF(CO) method demonstrated high reproducibility within individual mice.
• Emphysema model showed a significant 15% reduction in DF(CO).
• Fibrosis model exhibited a significant 41% reduction in DF(CO).

Conclusions:

• The developed DF(CO) method provides a quick and simple pulmonary function test for mouse models.
• DF(CO) effectively detects structural lung changes in emphysema and fibrosis.
• This method can also assess changes in pulmonary blood volume due to its dependence on CO uptake.