Prostasomes

Prostasomes were discovered in 1978 as submicrometre membranous vesicles (40-500 nm in diameter) secreted by the prostate gland epithelial cells into seminal fluid [cite journal | author = Ronquist G, Brody I| title = The prostasome: its secretion and function in man. | journal = Biochim Biophys Acta | volume = 822 | issue = 2 | pages = 203-18 | year = 1985 | pmid = 2992593 | doi = 10.1016/0304-4157(85)90008-5 | url = | issn = ] . They possess an unusual lipid composition and a tight and highly-ordered structure of their lipoprotein membranes resembling lipid raft. The physiological role of prostasomes implicates improvement of sperm motility and protection against attacks from the female immune defense during the passage to the egg [cite journal | author = Burden HP, Holmes CH, Persad R, Whittington K | title = Prostasomes--their effects on human male reproduction and fertility. | journal = Hum Reprod Update | volume = 12 | issue = 3 | pages = 283-92 | year = 2006 | pmid = 16373403 | doi = 10.1093/humupd/dmi052 | url = http://humupd.oxfordjournals.org/cgi/content/full/12/3/283 | issn = ] . Investigations have shown that cancerous prostate cells and prostate cells with low differentiation continue to produce and secrete prostasomes [cite journal | authors = Ronquist G, Nilsson BO | title = The Janus-faced nature of prostasomes: their pluripotency favours the normal reproductive process and malignant prostate growth. | journal = Prostate Cancer Prostatic Dis | volume = 7 | issue = 1 | pages = 21-31 | year = 2004 | pmid = 14999234 | doi = 10.1038/sj.pcan.4500684 | url = | issn = ] . The high incidence of prostate cancer in elderly men could take advantage of the immune protective activities supported by the prostasomes. Immunne regulating proteins found in prostasomes include: amino-peptidase N (CD13); dipeptidyl-peptidase IV (CD26); enkephalinase (neutral endopeptidase, CD10); angiotensin converting enzyme (ACE, CD143); tissue factor TF (CD142, thromboplastin); decay accelerator factor (CD55); protectin (CD59, inhibitor of MAC) and complement regulatory membrane cofactor protein (CD46) [Ronquist, G., Jin, M., Schrimpf, S. and Nilsson, B. O. (Motta, P. M. ed.) (1997) Prostasomes and human reproduction. Microscopy of Reproduction and Development: A Dynamic Approach pp. 213-219. Antonio Delfino Editore , Rome] [Ronquist, G., Carlsson, L., Larsson, A. and Nilsson, B. O. (Ronquist, G. and Nilsson, B. O. eds.) (2002) Prostasomes. Prostasomes: Proceedings from a symposium held at the Wenner-Gren Centre, Stockholm, June 2001 pp. 1-9. Portland Press , London] [cite journal | authors = Stewart AB, Anderson W, Delves G, Lwaleed BA, Birch B, Cooper A |title = Prostasomes: a role in prostatic disease? | journal = BJU Int | volume = 94 | issue = 4 | pages = 985-9 | year = 2004 | pmid = 15541114 | doi = 10.1111/j.1464-410X.2004.05091.x | url = | issn = ] . Prostasomes also contains high levels of divalent cations as: Zn²⁺, Ca²⁺ and Mg²⁺.

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