Calcium may be responsible for asthma symptoms
“Asthma cure could be in reach,” The Independent reports. Researchers have discovered that protein molecules called calcium-sensing receptors play a pivotal role in asthma. Drugs known to block these proteins already exist.
In asthma, the immune system mistakes harmless substances, such as pollen, as a threat. White blood cells and inflammatory proteins then collect in the airways. The inflammation causes the airways to constrict, leading to the breathing difficulties associated with asthma. This study found these proteins stimulate calcium-sensing receptors, which leads to further inflammation of the airways.
The research used mouse models of asthma and human airway tissue taken from asthmatic and non-asthmatic people. The researchers found increased numbers of these calcium-sensing receptors compared with healthy lung tissue. They concluded that this is one of the reasons for the exaggerated inflammatory response that occurs in asthma.
The drug calcityrol, which is used to treat osteoporosis, is known to block the actions of the receptors. It reduced inflammation of the airways when used in mice.
However, it is not clear that calcityrol could be a “cure” for asthma, as the initial inflammatory response by the immune system would still occur.
Though calcityrol pills are safe as a treatment for osteoporosis, it is not known whether the dose required to be effective in reducing the inflammation found in asthma would be safe.
The researchers plan to develop a version of the drug that can be inhaled to maximise its effectiveness and minimise side effects. They expect human trials to commence in a couple of years.