If an asthma patient inhales pollen, which consequence follows regarding airway smooth muscle?

💡 Explanation

In asthma, inhaled pollen triggers mast cell degranulation, releasing histamine. Histamine then binds to H1 receptors on airway smooth muscle cells, causing bronchoconstriction because this is the primary mechanism. Therefore, histamine mediates pollen-induced constriction, rather than direct epinephrine/adenosine effects or nitric oxide blocking calcium channels.

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