What is the central mediator released from mast cells during an allergic reaction that plays a role in airway obstruction?

A. Prostaglandins: Prostaglandins are lipid mediators released during inflammation that contribute to vasodilation, pain, and fever. While they play a role in inflammatory responses in the airways, they are not the primary mediator responsible for acute bronchoconstriction during an allergic reaction.

B. Histamine: Histamine is the central mediator released from mast cells during an allergic reaction. It binds to H₁ receptors in the respiratory tract, causing bronchoconstriction, increased vascular permeability, and mucus production, all of which contribute directly to airway obstruction and the clinical manifestations of allergic asthma.

C. Eicosanoid: Eicosanoids, such as leukotrienes and prostaglandins, are involved in the later stages of inflammation and contribute to sustained bronchoconstriction and edema. However, they are secondary mediators compared to histamine in the immediate airway response.

D. Bradykinin: Bradykinin is a peptide that promotes vasodilation, increased vascular permeability, and pain. It plays a minor role in airway inflammation but is not the central mediator responsible for acute airway obstruction in allergic reactions.

E. Omega-3: Omega-3 fatty acids are dietary components with anti-inflammatory properties. They do not function as mediators in allergic responses or cause airway obstruction, and their presence does not trigger mast cell–mediated bronchoconstriction.