Mouse sperm patch-clamp recordings reveal single Cl- channels sensitive to niflumic acid, a blocker of the sperm acrosome reaction.
Ion channels lie at the heart of gamete signaling. Understanding their regulation will improve our knowledge of sperm physiology, and may lead to novel contraceptive strategies. Sperm are tiny (approximately 3 microm diameter) and, until now, direct evidence of ion channel activity in these cells was lacking. Using patch-clamp recording we document here, for the first time, the presence of cationic and anionic channels in mouse sperm. Anion selective channels were blocked by niflumic acid (NA) (IC50 = 11 microM). The blocker was effective also in inhibiting the acrosome reaction induced by the zona pellucida, GABA or progesterone. These observations suggest that Cl- channels participate in the sperm acrosome reaction in mammals.
Espinosa
F
F
Depto. Genética y Fisiologia Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos.
de la Vega-Beltrán
J L
JL
López-González
I
I
Delgado
R
R
Labarca
P
P
Darszon
A
A
D000177:Acrosome / Q000502:physiology*; D000818:Animals; D002454:Cell Differentiation; D018118:Chloride Channels / Q000037:antagonists & inhibitors*; D004527:Egg Proteins / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects*; D008297:Male; D008562:Membrane Glycoproteins / Q000494:pharmacology; D008564:Membrane Potentials; D051379:Mice; D009544:Niflumic Acid / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D011374:Progesterone / Q000494:pharmacology; D011956:Receptors, Cell Surface; D013090:Spermatocytes / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D000072216:Zona Pellucida Glycoproteins; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D018118:Chloride Channels; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D000072216:Zona Pellucida Glycoproteins; D011374:Progesterone; D009544:Niflumic Acid; D005680:gamma-Aminobutyric Acid