{{Short description|Secretory vesicles within the immune system}} '''Specific granules''' are secretory vesicles found exclusively in cells of the immune system called granulocytes.

It is sometimes described as applying specifically to neutrophils,<ref name="urlDefinition: specific granule from Online Medical Dictionary">{{cite web |url=http://cancerweb.ncl.ac.uk/cgi-bin/omd?specific+granule |title=Definition: specific granule from Online Medical Dictionary }}</ref> and sometimes the term is applied to other types of cells.<ref name="pmid7334549">{{cite journal |vauthors=Okuda M, Takenaka T, Kawabori S, Ogami Y |title=Ultrastructural study of the specific granule of the human eosinophil |journal=J. Submicrosc. Cytol. |volume=13 |issue=3 |pages=465–71 |date=July 1981 |pmid=7334549 }}</ref>

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".<ref name="GreerWintrobe2008">{{cite book|author1=John P. Greer|author2=Maxwell Myer Wintrobe|title=Wintrobe's clinical hematology|url=https://books.google.com/books?id=68enzUD7BVgC&pg=PA173|access-date=10 November 2010|date=1 December 2008|publisher=Lippincott Williams & Wilkins|isbn=978-0-7817-6507-7|pages=173–}}</ref>

==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.<ref>{{OMIM|245480|SPECIFIC GRANULE DEFICIENCY; SGD}}</ref>

==References== {{reflist}}

==External links== * [http://nic.sav.sk/logos/books/scientific/node16.html Neutrophil granules at sav.sk] {{Webarchive|url=https://web.archive.org/web/20061127081936/http://nic.sav.sk/logos/books/scientific/node16.html |date=27 November 2006 }}

{{Granule contents}}

{{Use dmy dates|date=April 2017}}

{{DEFAULTSORT:Specific Granule}} Category:Organelles Category:Immunology

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