Potassium current in mature bovine spermatozoa.
Ion channels have been assigned a pivotal importance in various sperm functions and are therefore promising targets for contraceptive development. The lack of data on channel functionality and pharmacology has hampered this goal. This is a consequence of technical problems of applying electrophysiological techniques to spermatozoa due to their small size and form. By using a laminin coating to increase adherence of spermatozoa and nystatin in the patch pipette for pore formation, we have adapted the whole-cell recording technique to study currents in mature uncapacitated bovine spermatozoa. Employing these conditions, in the head region, patched spermatozoa could be transferred into the whole-cell configuration. For the first time we document an outward rectifying current in mature bovine spermatozoa was blocked by tetraethyl ammonium (TEA) chloride. The observation of a shift in the reversal potential as a response to changes in the extracellular concentration of K(+) ions allowed us to identify this current as K(+) selective. This result shows that K(+) channels in the head region of mature uncapacitated bovine spermatozoa can be suitably investigated using the whole-cell recording patch-clamp technique.
Marconi
Marcelo
M
Center for Reproductive Biotechnology, Laboratory of Neuroscience, Department of Preclinical Sciences, Faculty of Medicine, Universidad de La Frontera, Temuco, Chile.
Sánchez
Raul
R
Ulrich
Henning
H
Romero
Fernando
F
D000818:Animals; D002417:Cattle; D004553:Electric Conductivity; D008297:Male; D008564:Membrane Potentials; D009761:Nystatin; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D055366:Synaptic Potentials; D019789:Tetraethylammonium / Q000494:pharmacology
D015221:Potassium Channels; D009761:Nystatin; D019789:Tetraethylammonium; D011188:Potassium