Molecular Human Reproduction, Vol. 7, No. 2, 119-128,
February 2001
© 2001 European Society of Human Reproduction and Embryology
Testis and spermatogenesis |
Intracellular calcium store depletion and acrosome reaction in human spermatozoa: role of calcium and plasma membrane potential
1 University of Padova, Department of Medical and Surgical Sciences, Clinica Medica 3, Via Ospedale 105, 35128 Padova and 2 University of Ferrara, Department of Experimental and Diagnostic Medicine, Section of General Pathology, Via Borsari 46, 44100 Ferrara, Italy
Abstract
We evaluated the presence and role of internal calcium stores in human uncapacitated spermatozoa by determining the effects of two inhibitors of Ca2+ ATPase of the sarco-endoplasmic reticulum (SERCA–ATPase), thapsigargin and cyclopiazonic acid (CPA) on intracellular calcium concentrations, [Ca2+]i, plasma membrane potential and acrosome reaction. Using a fluorescent conjugate of thapsigargin, we localized internal Ca2+ stores on the acrosome, post-acrosomal region and sperm midpiece. SERCA–ATPase inhibitors induced a rise in [Ca2+]i both in Ca2+ and Ca2+-free media but under these latter conditions it was reduced with a progressive decline to baseline values; the re-addition of Ca2+-stimulated a rise in [Ca2+]i. This demonstrated that internal Ca2+ store depletion can evoke the opening of Ca2+-channels on sperm plasma membrane, thus showing the existence of `capacitative' Ca2+ entry into these specialized cells. The addition of thapsigargin to human spematozoa induced a dose-dependent increase in acrosome reaction percentages, but only when Ca2+ was present in the external medium. Plasma membrane potential monitoring showed that these inhibitors induced a depolarization dependent on Ca2+ influx from external medium and that this was preceded by a transient hyperpolarization caused by activation of Ca2+-dependent K+ channels. When K+-dependent plasma membrane hyperpolarization was inhibited, the thapsigargin- and CPA-stimulated rise in [Ca2+]i plasma membrane depolarization and acrosome reaction were abolished. In conclusion, the present study demonstrates that human spermatozoa possess internal Ca2+ stores and that the capacitative Ca2+ entry pathway present in these cells regulates important biological processes that are fundamental for the acrosome reaction.
calcium/channels/internal stores/membrane potential/spermatozoa
Notes
3 To whom correspondence should be addressed. E-mail: forestac{at}protec.it
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  D. Krapf, E. D. O'Brien, M. O. Cabada, P. E. Visconti, and S. E. Arranz Egg Water from the Amphibian Bufo arenarum Modulates the Ability of Homologous Sperm to Undergo the Acrosome Reaction in the Presence of the Vitelline Envelope Biol Reprod, February 1, 2009; 80(2): 311 - 319. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. L. Feng, Y. B. Han, A. Hershlag, and L. J. Zheng Impact of Ca2+ Flux Inhibitors on Acrosome Reaction of Hamster Spermatozoa J Androl, July 1, 2007; 28(4): 561 - 564. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Lawson, V. Dorval, S. Goupil, and P. Leclerc Identification and localisation of SERCA 2 isoforms in mammalian sperm Mol. Hum. Reprod., May 1, 2007; 13(5): 307 - 316. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. Thundathil, M. Anzar, and M. M. Buhr Na+/K+ATPase as a Signaling Molecule During Bovine Sperm Capacitation Biol Reprod, September 1, 2006; 75(3): 308 - 317. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Jimenez-Gonzalez, F. Michelangeli, C.V. Harper, C.L.R. Barratt, and S.J. Publicover Calcium signalling in human spermatozoa: a specialized 'toolkit' of channels, transporters and stores Hum. Reprod. Update, May 1, 2006; 12(3): 253 - 267. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. V. Harper and S. J. Publicover Reassessing the role of progesterone in fertilization--compartmentalized calcium signalling in human spermatozoa? Hum. Reprod., October 1, 2005; 20(10): 2675 - 2680. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Kumar and S. Meizel Nicotinic Acetylcholine Receptor Subunits and Associated Proteins in Human Sperm J. Biol. Chem., July 8, 2005; 280(27): 25928 - 25935. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Harper, L. Wootton, F. Michelangeli, L. Lefievre, C. Barratt, and S. Publicover Secretory pathway Ca2+-ATPase (SPCA1) Ca2+ pumps, not SERCAs, regulate complex [Ca2+]i signals in human spermatozoa J. Cell Sci., April 15, 2005; 118(8): 1673 - 1685. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Rossato, F. Ion Popa, M. Ferigo, G. Clari, and C. Foresta Human Sperm Express Cannabinoid Receptor Cb1, the Activation of Which Inhibits Motility, Acrosome Reaction, and Mitochondrial Function J. Clin. Endocrinol. Metab., February 1, 2005; 90(2): 984 - 991. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. V. Harper, C. L. R. Barratt, and S. J. Publicover Stimulation of Human Spermatozoa with Progesterone Gradients to Simulate Approach to the Oocyte: INDUCTION OF [Ca2+]i OSCILLATIONS AND CYCLICAL TRANSITIONS IN FLAGELLAR BEATING J. Biol. Chem., October 29, 2004; 279(44): 46315 - 46325. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Tosti and R. Boni Electrical events during gamete maturation and fertilization in animals and humans Hum. Reprod. Update, January 1, 2004; 10(1): 53 - 65. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Fukami, M. Yoshida, T. Inoue, M. Kurokawa, R. A. Fissore, N. Yoshida, K. Mikoshiba, and T. Takenawa Phospholipase C{delta}4 is required for Ca2+ mobilization essential for acrosome reaction in sperm J. Cell Biol., April 14, 2003; 161(1): 79 - 88. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Dorval, M. Dufour, and P. Leclerc Role of protein tyrosine phosphorylation in the thapsigargin-induced intracellular Ca2+ store depletion during human sperm acrosome reaction Mol. Hum. Reprod., March 1, 2003; 9(3): 125 - 131. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. De Blas, M. Michaut, C. L. Trevino, C. N. Tomes, R. Yunes, A. Darszon, and L. S. Mayorga The Intraacrosomal Calcium Pool Plays a Direct Role in Acrosomal Exocytosis J. Biol. Chem., December 13, 2002; 277(51): 49326 - 49331. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Revelli, D. Ghigo, F. Moffa, M. Massobrio, and I. Tur-Kaspa Guanylate Cyclase Activity and Sperm Function Endocr. Rev., August 1, 2002; 23(4): 484 - 494. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. Kirkman-Brown, E. L. Punt, C. L. R. Barratt, and S. J. Publicover Zona Pellucida and Progesterone-Induced Ca2+ Signaling and Acrosome Reaction in Human Spermatozoa J Androl, May 1, 2002; 23(3): 306 - 315. [Full Text] [PDF]
|
|