Agonist-activated Ca2+ influx and Ca2+-dependent Cl- channels in Xenopus ovarian follicular cells: Functional heterogeneity within the cell monolayer
Por:
Arellano, RO, Robles-Martinez, L, Serrano-Flores, B, Vazquez-Cuevas, F, Garay, E
Publicada:
1 oct 2012
Resumen:
Xenopus follicles are endowed with specific receptors for ATP, ACh, and AII, transmitters proposed as follicular modulators of gamete growth and maturation in several species. Here, we studied ion-current responses elicited by stimulation of these receptors and their activation mechanisms using the voltage-clamp technique. All agonists elicited Cl- currents that depended on coupling between oocyte and follicular cells and on an increase in intracellular Ca2+ concentration ([Ca2+]i), but they differed in their activation mechanisms and in the localization of the molecules involved. Both ATP and ACh generated fast Cl- (FCl) currents, while AII activated an oscillatory response; a robust Ca2+ influx linked specifically to FCl activation elicited an inward current (Iiw,Ca) which was carried mainly by Cl- ions, through channels with a sequence of permeability of SCN-?>?I-?>?Br-?>?Cl-. Like FCl, Iiw,Ca was not dependent on oocyte [Ca2+]i; instead both were eliminated by preventing [Ca2+]i in
Filiaciones:
Arellano, RO:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Juriquilla Queretaro 76230, Queretaro, Mexico
Robles-Martinez, L:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Juriquilla Queretaro 76230, Queretaro, Mexico
Serrano-Flores, B:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Juriquilla Queretaro 76230, Queretaro, Mexico
Vazquez-Cuevas, F:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Juriquilla Queretaro 76230, Queretaro, Mexico
Garay, E:
Univ Nacl Autonoma Mexico, Inst Neurobiol, Dept Neurobiol Celular & Mol, Juriquilla Queretaro 76230, Queretaro, Mexico
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