HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 72/5/1275    most recent biolreprod.104.038448v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barfield, J.P. Articles by Cooper, T.G. Search for Related Content PubMed PubMed Citation Articles by Barfield, J.P. Articles by Cooper, T.G. Agricola Articles by Barfield, J.P. Articles by Cooper, T.G.

The Effects of Putative K⁺ Channel Blockers on Volume Regulation of Murine Spermatozoa¹

Institute of Reproductive Medicine of the University,³ D-48129 Münster, Germany Department of Biological Sciences,⁴ University of New Orleans, New Orleans, Louisiana 70148

Volume regulation is a necessary task for spermatozoa as the osmolarity of female tract fluids is lower than that in the epididymis and because the disruption of it in transgenic mice results in infertility. As the specific mechanisms behind this phenomenon are unknown, spermatozoa from mice were screened for sensitivities to inhibitors known to affect specific channels involved in volume regulation of somatic cells. Spermatozoa from the cauda epididymidis were exposed to physiological hypotonic conditions with and without inhibitor. Flow cytometric forward scatter measurements were taken to indicate relative sperm size at 5 and 75 min of incubation. The presence of quinine (0.8 mM), cadmium (0.2 mM), flecainide (100 µM), 4-aminopyridine (4 mM), barium (1 mM), clofilium (10 µM), and phrixotoxin (100 nM) for 75 min resulted in significantly higher forward scatter values than sperm incubated in medium without an inhibitor. These results imply that channels potentially involved in volume regulation of murine spermatozoa include the voltage-dependent Kv1.4 (also known as KCNA1), Kv1.5 (KCNA5), Kv4.1 (KCND1), Kv4.2 (KCND2), Kv4.3 (KCND3), mink (KCNE1), and acid-sensitive TASK2 (KCNK5) and TASK3 (KCNK9). Western blots confirmed the presence of Kv1.5 and TASK2 proteins in sperm plasma membranes at similar (Kv1.5) or higher (TASK2) molecular weight than in somatic cells. Incubation in a different pH did not reveal acid sensitivity of volume regulation. Volume regulation of spermatozoa may involve novel voltage-gated and pH-sensitive potassium channels, which could be valuable targets for the development of a posttesticular male contraceptive.

epididymis, fertilization, gamete biology, male reproductive tract, sperm

² Correspondence: T.G. Cooper, Institute of Reproductive Medicine of the University, Domagkstrasse 11, D-48129 Münster, Germany. FAX: 49 251 835 6093; TrevorG.Cooper{at}ukmuenster.de

This article has been cited by other articles:

				C Callies, T G Cooper, and C H Yeung Channels for water efflux and influx involved in volume regulation of murine spermatozoa Reproduction, October 1, 2008; 136(4): 401 - 410. [Abstract] [Full Text] [PDF]

				T G Cooper, J P Barfield, and C H Yeung The tonicity of murine epididymal spermatozoa and their permeability towards common cryoprotectants and epididymal osmolytes Reproduction, May 1, 2008; 135(5): 625 - 633. [Abstract] [Full Text] [PDF]

				T. Klein, T.G. Cooper, and C.H. Yeung The Role of Potassium Chloride Cotransporters in Murine and Human Sperm Volume Regulation Biol Reprod, December 1, 2006; 75(6): 853 - 858. [Abstract] [Full Text] [PDF]

				S. Fetic, C.-H. Yeung, B. Sonntag, E. Nieschlag, and T. G. Cooper Relationship of Cytoplasmic Droplets to Motility, Migration in Mucus, and Volume Regulation of Human Spermatozoa J Androl, March 1, 2006; 27(2): 294 - 301. [Abstract] [Full Text] [PDF]

				X. Bai, H. A. Lacey, S. L. Greenwood, P. N. Baker, M. A. Turner, C. P. Sibley, and G. K. Fyfe TASK Channel Expression in Human Placenta and Cytotrophoblast Cells Reproductive Sciences, January 1, 2006; 13(1): 30 - 39. [Abstract] [PDF]

				J.P. Barfield, C.H. Yeung, and T.G. Cooper Characterization of potassium channels involved in volume regulation of human spermatozoa Mol. Hum. Reprod., December 1, 2005; 11(12): 891 - 897. [Abstract] [Full Text] [PDF]

				C.H. Yeung, J.P. Barfield, and T.G. Cooper Chloride Channels in Physiological Volume Regulation of Human Spermatozoa Biol Reprod, November 1, 2005; 73(5): 1057 - 1063. [Abstract] [Full Text] [PDF]