In vivo modeling systems for chronic obstructive pulmonary disease

Concerning pharmacological characterization of drugs which may be effective in the treatment of COPD, just as there is no single animal model, we must also remember that no single drug has provided consistent efficacy in the clinical treatment of the disease. Therefore, a potential therapeutic drug regimen must be assessed in a model which appropriately reflects a particular aspect of the disease (i.e., inflammatory cell infiltration, mucus hypersecretion, airway wall remodeling, emphysema, and systemic disease). Because some agents (agonists, inhibitors or antagonists) may work in only certain animals, the appropriate stimulus and the particular therapeutic drug standard to which it should be compared may be species and strain dependent. Therefore, whenever possible, careful in vitro or ex vivo coordination and comparison of the activity found in tissues from the species and models selected to healthy and diseased human tissues should be made. Although rational therapeutic approaches based on inhibitory activity in a number of these models may increase the level of confidence in finding efficacy in the disease state, one should not oversimplify the etiology of the disease to fit the overall profile of the drug.