FINDINGS from an animal study have provided a new way of thinking about asthma attacks. One of the researchers involved in the study, Dr Richard Wilson, Department of Physiology and Pharmacology University of Calgary, Calgary, Canada, declared: “This idea is going to come out of left field for some people. It is a completely new way to think about how the body responds during an asthma attack.”
The researchers were investigating asthma attack in a rat model, during which they discovered a potential cause for airway narrowing during asthma attacks caused by allergens: carotid bodies. The proposed mechanism for this is that lysophosphatidic acid (LPA) levels in the lungs increase during an asthma attack, and the increased LPA levels stimulate the carotid bodies. As a result of this stimulation, the carotid bodies increase lung resistance. In healthy individuals this increased lung resistance is normal because the mechanism prevents airway collapse when breathing rates increase. However, as a result of the inflamed airways associated with asthma, carotid body activation and the knock-on lung resistance increase results in breathing difficulties.
Following the identification of the link between carotid body stimulation and asthma, researchers examined the impact of blocking carotid body receptors, preventing the neurones from detecting increased LPA levels. Blocking the receptors prevented an increase in lung resistance and the asthma attacks were avoided in the rat model, suggesting a potential mechanism of treatment.
While this is a finding that may be of interest to those developing new therapeutic options for asthma attacks induced by allergens, it should be noted that these findings were from a study in rats. There are a number of steps that need to take place before these results could lead to a viable treatment in humans. However, the researchers hope that their results will stimulate further research into this newly-discovered link between carotid bodies and asthma attacks.