When mast cells degranulate, what is one of the pharmacological mediators they release?

Mast cells are crucial components of the immune system, specifically involved in allergic reactions and responses to pathogens. When they undergo a process called degranulation, they release several pharmacological mediators that play important roles in inflammation and immune responses. Among these mediators, histamines are particularly significant.

Histamines are stored in granules within mast cells and are released into the surrounding tissue during degranulation. They contribute to various physiological changes, including increased vascular permeability, smooth muscle contraction, and stimulation of gastric acid secretion. These effects are pivotal in the context of allergic reactions, where histamine release leads to symptoms such as itching, swelling, and redness, as well as bronchoconstriction in conditions like asthma.

Other mediators released by mast cells upon degranulation include cytokines and leukotrienes, but in this context, histamine is one of the primary and well-known mediators contributing to immediate hypersensitive responses. Thus, recognizing histamines as a key product of mast cell degranulation highlights their role in both normal immune function and the pathophysiology of allergic reactions.