|Merocrine or eccrine – by exocytosis|
|Apocrine – by membrane budding (loss of cytoplasm)|
|Holocrine – by membrane rupture|
Holocrine (from Ancient Greek ὅλος; hólos, “whole, entire” + κρῑ́νω; krī́nō, “to separate”) is a term used to classify the mode of secretion in exocrine glands in the study of histology. Holocrine secretions are produced in the cytoplasm of the cell and released by the rupture of the plasma membrane, which destroys the cell and results in the secretion of the product into the lumen.
Holocrine gland secretion is the most damaging (to the cell itself and not to the host which begot the cell) type of secretion, with merocrine secretion being the least damaging and apocrine secretion falling in between.
Examples of holocrine glands include the sebaceous glands of the skin and the meibomian glands of the eyelid. The sebaceous gland is an example of a holocrine gland because its product of secretion (sebum) is released with remnants of dead cells.
- Yoshizawa, Katsuhiko (2018-01-01), Suttie, Andrew W. (ed.), "Chapter 20 - Specialized Sebaceous Glands—Zymbal's Gland, Preputial Gland, Clitoral Gland, and Perianal Gland", Boorman's Pathology of the Rat (Second Edition), Boston: Academic Press, pp. 347–365, doi:10.1016/b978-0-12-391448-4.00020-4, ISBN 978-0-12-391448-4, retrieved 2020-10-22
- Campbell, Karen L.; Lichtensteiger, Carol A. (2004-01-01), Campbell, Karen L. (ed.), "1 - STRUCTURE AND FUNCTION OF THE SKIN", Small Animal Dermatology Secrets, Philadelphia: Hanley & Belfus, pp. 1–9, doi:10.1016/b978-1-56053-626-0.50005-7, ISBN 978-1-56053-626-0, retrieved 2020-10-22
- Sundberg, John P.; Booth, Carmen J.; Nanney, Lillian B.; Fleckman, Philip; King, Lloyd E. (2018-01-01), Treuting, Piper M.; Dintzis, Suzanne M.; Montine, Kathleen S. (eds.), "24 - Skin and Adnexa", Comparative Anatomy and Histology (Second Edition), San Diego: Academic Press, pp. 511–542, doi:10.1016/b978-0-12-802900-8.00024-5, ISBN 978-0-12-802900-8, retrieved 2020-10-22
- Victor Eroschenko, diFiore's Atlas of Histology with functional correlations, Lippincott Williams & Wilkins, 10th edition, 2005. p. 41
- Nair, K. P. Prabhakaran (2013-01-01), Nair, K. P. Prabhakaran (ed.), "15 - The Agronomy and Economy of Ginger", The Agronomy and Economy of Turmeric and Ginger, Oxford: Elsevier, pp. 225–292, doi:10.1016/b978-0-12-394801-4.00015-6, ISBN 978-0-12-394801-4, retrieved 2020-10-22