Asthma and Airways
The airways (also known as the bronchioles) are surrounded by layers of smooth muscle. This muscle is not under voluntary control; instead, it is controlled by the autonomic nervous system, which is the portion of the nervous system that automatically controls things such as breathing and heart rate. As MedlinePlus explains, these muscles can tighten in some patients, leading to asthma attacks. In patients with emphysema or chronic obstructive pulmonary disease (COPD), narrowed bronchioles also make breathing difficult. Albuterol works to relax the muscles in the airways, allowing the bronchioles to expand, which makes breathing easier.
Abluterol Mechanism of Action
The smooth muscles around the airways are controlled by the autonomic nervous system. These muscle cells contain special proteins called receptors on their surface, which allows the autonomic nervous system to give directions to the muscle cells. When the autonomic nervous system wants to constrict or relax these muscles, it secretes special chemicals that bind to the receptors. Depending on which receptors are activated, the muscle will either relax or constrict. As DrugBank explains, albuterol binds to beta(2)-adrenergic receptors. When albuterol binds to these receptors, it stimulates the production of a chemical called cyclic AMP. Increased levels of this chemical reduce the amount of calcium that enters into the muscles. Calcium causes muscles to contract, so reduced calcium levels relax the muscles around the airways.
Immune Effects
An asthma attack is caused by the immune system reacting strongly to something that has been inhaled. When this happens, it leads to inflammation, which causes swelling of the airways and contributes to their narrowing. As EMedTV explains, albuterol has some effects on a type of immune cell called a mast cell. By inhibiting the activity of mast cells, albuterol can help reduce the immune reaction and inflammation that causes asthma attacks.
