Dual regulation of the T-type Ca2+ current by serum albumin and ß- estradiol in mammalian spermatogenic cells
Por:
Espinosa F., López-González I., Muñoz-Garay C., Felix R., De La Vega-Beltrán J.L., Kopf G.S., Visconti P.E., Darszon A.
Publicada:
1 ene 2000
Resumen:
This study provides evidence for a novel mechanism of voltage-gated Ca2+ channel regulation in mammalian spermatogenic cells by two agents that affect sperm capacitation and the acrosome reaction (AR). Patch-clamp experiments demonstrated that serum albumin induced an increase in Ca2+ T current density in a concentration-dependent manner, and significant shifts in the voltage dependence of both steady-state activation and inactivation of the channels. These actions were not related to the ability of albumin to remove cholesterol from the membrane. In contrast, ?-estradiol significantly inhibited Ca2+ channel activity in a concentration-dependent and essentially voltage-independent fashion. In mature sperm this dual regulation may influence capacitation and/or the AR. (C) 2000 Federation of European Biochemical Societies.
Filiaciones:
Espinosa F.:
Dept. of Genet. and Molec. Physiol., Inst. Biotech., UNAM, Ave. U., Cuernavaca, Mexico
López-González I.:
Dept. of Genet. and Molec. Physiol., Inst. Biotech., UNAM, Ave. U., Cuernavaca, Mexico
Muñoz-Garay C.:
Dept. of Genet. and Molec. Physiol., Inst. Biotech., UNAM, Ave. U., Cuernavaca, Mexico
Felix R.:
Dept. of Genet. and Molec. Physiol., Inst. Biotech., UNAM, Ave. U., Cuernavaca, Mexico
Department of Physiology, Biophys. Neurosci., Cinvestav-IPN, Mexico City, Mexico
De La Vega-Beltrán J.L.:
Dept. of Genet. and Molec. Physiol., Inst. Biotech., UNAM, Ave. U., Cuernavaca, Mexico
Kopf G.S.:
Ctr. Res. Repro. and Women's Hlth., Univ. of Pennsylvania Medical Center, Philadelphia, PA, United States
Visconti P.E.:
Dept. of Anatomy and Cell Biology, University of Virginia, Charlottesville, VA, United States
Darszon A.:
Dept. of Genet. and Molec. Physiol., Inst. Biotech., UNAM, Ave. U., Cuernavaca, Mexico
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