Specific granule explained

Specific granules are secretory vesicles found exclusively in cells of the immune system called granulocytes.

It is sometimes described as applying specifically to neutrophils,^[1] and sometimes the term is applied to other types of cells.^[2]

These granules store a mixture of cytotoxic molecules, including many enzymes and antimicrobial peptides, that are released by a process called degranulation following activation of the granulocyte by an immune stimulus.

Specific granules are also known as "secondary granules".^[3]

Contents

Examples of cytotoxic molecule stored by specific granules in different granulocytes include:

• Neutrophil: alkaline phosphatase, lactoferrin, lysozyme, NADPH oxidase
• Eosinophil: cathepsin, major basic protein
• Basophil: heparin, histamine (not directly cytotoxic)

Clinical significance

A specific granule deficiency can be associated with CEBPE.

External links

• Neutrophil granules at sav.sk

Notes and References

1. Web site: Definition: specific granule from Online Medical Dictionary .
2. Okuda M, Takenaka T, Kawabori S, Ogami Y . Ultrastructural study of the specific granule of the human eosinophil . J. Submicrosc. Cytol. . 13 . 3 . 465–71 . July 1981 . 7334549 .
3. Book: John P. Greer. Maxwell Myer Wintrobe. Wintrobe's clinical hematology. 10 November 2010. 1 December 2008. Lippincott Williams & Wilkins. 978-0-7817-6507-7. 173–.