Degranulation

Degranulation is a cellular process that releases antimicrobial, cytotoxic, or other molecules from secretory vesicles called granules found inside some cells.

Granules from mast cells mediate processes such as "vasodilation, vascular homeostasis, innate and adaptive immune responses, angiogenesis, and venom detoxification.

The mast cell releases a mixture of compounds, including histamine, proteoglycans, serotonin, and serine proteases from its cytoplasmic granules.

[2] In a similar mechanism, activated eosinophils release preformed mediators such as major basic protein, and enzymes such as peroxidase, following interaction between their Fc receptors and IgE molecules that are bound to large parasites like helminths.

[3][4] Degranulation in neutrophils can occur in response to infection, and the resulting granules are released in order to protect against tissue damage.

The degranulation process in a Mast cell. 1 = antigen ; 2 = IgE ; 3 = FcεR1 ; 4 = preformed mediators ( histamine , proteases , chemokines , heparin ); 5 = granules; 6 - Mast cell; 7 - newly formed mediators ( prostaglandins , leukotrienes , thromboxanes , platelet-activating factor )