The structural components of the airway

Furthermore, it is also likely that the interaction of these inflammatory cells with airway tissues determines the intensity of AHR. At present, quantifying the interactive contribution of cellular elements and resident components to the overall inflammatory reaction is not readily available. Therefore, to identify the contributions of inflammation to AHR, it is important to consider the many aspects of this process, including the location of the cells (ie, lumen vs bronchial wall) and cell type as well as the many mediators associated with the injury to the airway. The present data, however, suggest that it is likely that structural changes of the airway are the greater contributor to AHR than the development of inflammation.

The structural components of the airway previously described include airway smooth muscle. There has been considerable interest in dissecting the contribution of airway remodeling and their relationship to smooth muscle and/or features of airway smooth muscle contractile responses to the presence of AHR in asthma. As noted, the measurement of AHR is characterized by excessive narrowing to contractile substances that cause no effect in normal subjects and a response at a smaller dose Viagra online Australia.

These characteristics represent two changes: an increased sensitivity and an ability of the airway smooth muscle to narrow excessively. Some believe the response to contraction at a lower dose (ie, increased sensitivity) may represent the less significant change, and it is the exaggerated airway narrowing that is more important in asthma and the resulting altered physiology. Efforts are ongoing to sort out that the contribution of airway remodeling and altered smooth muscle to AHR. Pare et al, for example, present convincing evidence that airway wall remodeling is a major contributor to the excessive airway narrowing in asthma.

These same investigators have pointed out that the excessive deposition of collagen and thickening of the airway wall could protect against excessive airway narrowing Canadian Pharmacy Online. Thus, the balance between these changes can lead to opposite effects. In contrast, Oliver et al have convincing evidence that the increased muscle mass in asthma is a dominant factor contributing to AHR.

Comments are closed, but you can leave a trackback: Trackback URL.