Modeling asthma and COPD in animals: A pointless exercise?

Animal modeling has been essential to the development of every drug used to treat asthma and chronic obstructive pulmonary disease (COPD). Determining the safety and efficacy of new therapeutics will also depend upon animal experimentation, and future targets for therapeutic intervention will probably be identified during careful experimentation using animals. Animal modeling of chronic diseases is made possible by the fact that the processes associated with the regulation of breathing, gas exchange, airway smooth-muscle contraction and relaxation, blood flow through the pulmonary and bronchial vasculature, inflammatory cell recruitment, mucus secretion, mucociliary clearance and airway surface liquid composition are highly conserved in mammals. This conservation is apparent at the whole-organ level and also at the level of the cell and the genome. The subtleties of how the airways and lungs are regulated and experimentally measured in different species make the more complex processes associated with asthma and COPD difficult to faithfully model or duplicate in mammals, particularly in mammals such as rodents that are only distantly related to humans.