Maitotoxin potently promotes Ca2+ influx in mouse spermatogenic cells and sperm, and induces the acrosome reaction.
J Cell Physiol
; 206(2): 449-56, 2006 Feb.
Article
em En
| MEDLINE
| ID: mdl-16155908
Maitotoxin (MTX), a potent marine toxin, activates Ca2+ entry via nonselective cation channels in a wide variety of cells. The identity of the channels involved in MTX action remains unknown. In mammalian sperm, Ca2+ entry through store-operated channels regulates a number of physiological events including the acrosome reaction (AR). Here we report that MTX produced an increase in the intracellular concentration of Ca2+ ([Ca2+]i) in spermatogenic cells that depended on extracellular Ca2+. Ni2+ and SKF96365 diminished the MTX-activated Ca2+ uptake, at concentrations they inhibit store-operated channels, and in a similar manner as they inhibit the Ca2+ influx activated following depletion of intracellular stores by thapsigargin (Tpg). In addition, MTX significantly increased [Ca2+]i in single mature sperm and effectively induced the AR with a half-maximal concentration (ED50) of approximately 1.1 nM. Notably, SKF96365 similarly inhibited the MTX-induced increase in sperm [Ca2+]i and the AR triggered by the toxin, Tpg and zona pellucida. These results suggest that putative MTX-activated channels may be involved in the Ca2+ influx required for mouse sperm AR.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espermatozoides
/
Acrossomo
/
Cálcio
/
Oxocinas
/
Toxinas Marinhas
Limite:
Animals
Idioma:
En
Revista:
J Cell Physiol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Estados Unidos