Skip Navigation


Mol. Hum. Reprod. Advance Access originally published online on January 18, 2006
Molecular Human Reproduction 2005 11(12):881-889; doi:10.1093/molehr/gah245
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
11/12/881    most recent
gah245v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (2)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Bray, C.
Right arrow Articles by Meizel, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bray, C.
Right arrow Articles by Meizel, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Acetylcholine causes an increase of intracellular calcium in human sperm

C. Bray1, J.-H. Son and S. Meizel

Department of Cell Biology and Human Anatomy, School of Medicine, University of California at Davis, One Shields Avenue, Davis, CA, USA

1 To whom correspondence should be addressed at: Department of Cell Biology and Human Anatomy, School of Medicine, University of California at Davis, One Shields Avenue, Davis, CA, USA. E-mail: cmbray{at}ucdavis.edu

Sperm nicotinic acetylcholine receptors (nAChRs) can influence motility and the initiation of acrosome reaction (AR). We report that AR initiation by acetylcholine (ACh) in capacitated human sperm requires both Na+ and Ca2+ in the external medium. Pre-incubation with 50 µM 3-quinuclidinyl benzilate (QNB) or 50 nM strychnine failed to inhibit the ACh-initiated AR, demonstrating that muscarinic AChRs and nAChRs containing {alpha}9 subunits do not mediate this event. Choline (2.5, 5 and 10 mM), a highly specific but low potency agonist of the {alpha}7 nAChR initiated AR, with its effect blocked by the nAChR antagonist methyllycaconitine (MLA). ACh (50–400 µM) stimulated a small transient rise in the intracellular Ca2+ in sperm populations loaded with FURA-2, with 200 µM ACh being maximal (146 nM ± 23 SEM). The nAChR antagonists, {alpha}-bungarotoxin ({alpha}-BTX) and MLA, reduced the ACh-initiated Ca2+ rise by 75 and 78%, respectively, demonstrating the majority of the rise is mediated through nAChRs containing {alpha}7 or {alpha}9 subunits. Single cell imaging studies using FLUO-3 resolved two patterns of ACh-stimulated Ca2+ increase in the sperm head: 94% of responding sperm displayed a rise (59.6% ± 5.7 SEM increase from resting fluorescence intensity), returning to resting levels over a period of 2–3 min. The remaining sperm (6%) displayed a sharp spike of Ca2+ (~1 min; 86% ± 4.3 SEM change in fluorescence intensity), followed by abrupt loss of fluorescence, a pattern suggestive of AR. A Ca2+ influx in the sperm midpiece appeared to accompany the Ca2+ influx seen in the head. These observations confirm an ionotropic role for nAChRs in sperm function.

Key words: calcium/nicotinic acetylcholine receptors/sperm


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
F. Levitin, M. Weiss, Y. Hahn, O. Stern, R. L. Papke, R. Matusik, S. R. Nandana, R. Ziv, E. Pichinuk, S. Salame, et al.
PATE Gene Clusters Code for Multiple, Secreted TFP/Ly-6/uPAR Proteins That Are Expressed in Reproductive and Neuron-rich Tissues and Possess Neuromodulatory Activity
J. Biol. Chem., June 13, 2008; 283(24): 16928 - 16939.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.