A protease called neutrophil elastase exists in the neu-trophil granule. This protease effectively digests foreign bodies that come into the neutrophils by phagocytosis. In acute lung injury, activated neutrophils leak some elastase into the microcirculation. Under normal conditions, released neutrophil elastase in the blood is immediately inactivated by a1-antitrypsin (or a1 protease inhibitor). However, a1-antitrypsin is easily inactivated by both ROS and RNS; thus neutrophil elastase can damage the microvasculature, contributing to edema formation (Figure 1). Recently, the specific neutrophil elastase inhibitor ONO-5046 was shown to be effective in acute lung injury and is now on the market for clinical use in several countries.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.