GENERAL HISTOLOGY

Detailed explanation-1: -The mast cell secretes histamine by exocytosis when it is stimulated immunologically by binding of a specific antigen to IgE molecules in the cell membrane. Histamine secretion may also be induced by non-immunological stimulators such as polymeric amines, neuropeptides and calcium-ionophores.

Detailed explanation-2: -Mast cells play an important role in how the immune system responds to certain bacteria and parasites and they help control other types of immune responses. They contain chemicals such as histamine, heparin, cytokines, and growth factors.

Detailed explanation-3: -Mast cells synthesize and secrete histamine, proteases, prostaglandin D2, leukotrienes, heparin, and a variety of cytokines, many of which are implicated in CVD (36, 93–100).

Detailed explanation-4: -In the skin, antigens, via IgE, activate mast cells in the deep layers of connective tissue. Mast cells release histamine as well as other vasoactive molecules, which cause urticaria (hives).

Detailed explanation-5: -When mast cells detect a substance that triggers an allergic reaction (an allergen), they release histamine and other chemicals into the bloodstream. Histamine makes the blood vessels expand and the surrounding skin itchy and swollen.