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Prostasomes are neuroendocrine‐like vesicles in human semen
Author(s) -
Stridsberg Mats,
Fabiani Roberto,
Lukinius Agneta,
Ronquist Gunnar
Publication year - 1996
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/(sici)1097-0045(199611)29:5<287::aid-pros3>3.0.co;2-7
Subject(s) - chromogranin a , synaptophysin , organelle , microvesicles , vesicle , biology , seminal vesicle , spermatozoon , microbiology and biotechnology , endocrinology , chemistry , medicine , prostate , immunohistochemistry , immunology , ultrastructure , biochemistry , anatomy , membrane , microrna , cancer , gene
BACKGROUND Prostasomes are prostate‐derived organelles that exist extracellularly in human seminal plasma. METHODS In this study, we have investigated and characterized human prostasomes with regard to their contents of synaptophysin, members of the chromogranin family, and some neuropeptides. RESULTS By radioimmunoassay measurement and electron microscopy we show the presence of the neuroendocrine markers chromogranin B, neuropeptide Y, and vasoactive intestinal polypeptide in about equimolar amount in human prostasomes and chromogranin A in about 2% of that amount. To our knowledge, such a high ratio of chromogranin B to chromogranin A has never before been observed. The membrane‐bound protein synaptophysin, a well‐established immunocytochemical marker for neuroendocrine cells and neurones, was also detected. Hence, we show that synaptophysin could be used as a marker for intact prestasomes. CONCLUSIONS The presence of synaptophysin has recently been shown in the serotonin‐containing vesicles in platelets. A protein with a similar structure denoted granulophysin has been found in granulocytes and prostasomes. It is suggested that synaptophysin and granulophysin molecules are members of a family of proteins, maybe expressed in all cells that have regulated release of granule content. Our presented data indicate a neurotransmittor function of the prostasomes. The target cells are however not known but could be either the spermatozoa, the epithelial mucous cells of the uterus or tubas or perhaps the ovum. © 1996 Wiley‐Liss, Inc.