Abstract
Intravital microscopy (IVM) offers unique possibilities for the observation of biological processes and disease related mechanisms in vivo. Especially for anatomically complex and dynamic organs such as the lung and its main functional unit, the alveolus, IVM provides exclusive advantages in terms of spatial and temporal resolution. By the use of lung windows, which have advanced and improved over time, direct access to the lung surface is provided. In this review we will discuss two main topics, namely alveolar dynamics and perfusion from the perspective of IVM-based studies. Of special interest are unanswered questions regarding alveolar dynamics such as: What are physiologic alveolar dynamics? How do these dynamics change under pathologic conditions and how do those changes contribute to ventilator-induced lung injury? How can alveolar dynamics be targeted in a beneficial way? With respect to alveolar perfusion IVM has propelled our understanding of the pulmonary microcirculation and its perfusion, as well as pulmonary vasoreactivity, permeability and immunological aspects. Whereas the general mechanism behind these processes are understood, we still lack a proper understanding of the complex, multidimensional interplay between alveolar ventilation and microvascular perfusion, capillary recruitment, or vascular immune responses under physiologic and pathologic conditions. These are only part of the unanswered questions and problems, which we still have to overcome. IVM as the tool of choice might allow us to answer part of these questions within the next years or decades. As every method, IVM has advantages as well as limitations, which have to be taken into account for data analysis and interpretation, which will be addressed in this review.
Highlights
Intravital microscopy (IVM) is a two-dimensional imaging technique that allows for visualization of biological processes in vivo
By IVM of dog lungs in an open chest approach via a glass coverslip that was carefully lowered onto the lung surface, the authors observed a small extent of isotropic alveolar distention during lung inflation, yet only up to 20% of total lung capacity (TLC), with no detectable change in alveolar volume with further increases in lung volume
While IVM in intact, live animals – ideally under minimally invasive, closed chest conditions or even under spontaneous ventilation – is the gold standard for the visualization of alveolar dynamics, a common alternative – albeit less physiological – model used to analyze alveolar dynamics that allows for optimal control of ventilation and perfusion are excised, mechanically ventilated and constantly perfused lungs
Summary
Intravital microscopy (IVM) is a two-dimensional imaging technique that allows for visualization of biological processes in vivo. While IVM in intact, live animals – ideally under minimally invasive, closed chest conditions or even under spontaneous ventilation – is the gold standard for the visualization of alveolar dynamics, a common alternative – albeit less physiological – model used to analyze alveolar dynamics that allows for optimal control of ventilation and perfusion are excised, mechanically ventilated and constantly perfused lungs By this approach, Namati et al (2008) observed alveolar distension during lung inflation, yet at the end of inspiration the number of alveoli increased while alveolar volume decreased. These findings highlight the potential of IVM to unravel novel mechanisms of lung immunosurveillance and the roles of innate and adaptive immune cells in lung health and disease
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
