The presence on pig oolemma of voltage gated Ca channels (VGCC), whose activity can be influenced by depolarisation, has been investigated exposing the oocytes to a chemical depolarisation reproducing the physiological one. To this aim and to characterise the type of VGCC present, we analysed intracellular Ca variations during perfusion of oocytes with physiological or depolarising solutions containing different selective inhibitors of VGCC. We also evaluated the effect of their activation or inhibition on oocyte maturation and the pathway involved in transduction of the depolarising stimulus to the oocyte. The results demonstrate that P type VGCC are present on pig oolemma and that their activation by depolarisation produces a prompt a sustained Ca raise able to induce the resumption of oocyte meiotic maturation through the transduction pathway involving the Ca-calmodulin dependent kinase (CaMKII).[...]
P-type Ca channel activation by membrane depolarisation induces maturation in pig oocytes
GIOIA, Luisa;BARBONI, Barbara;TURRIANI, Maura;CAPACCHIETTI, Giulia;LUCIDI, Pia;MATTIOLI, Mauro
2005-01-01
Abstract
The presence on pig oolemma of voltage gated Ca channels (VGCC), whose activity can be influenced by depolarisation, has been investigated exposing the oocytes to a chemical depolarisation reproducing the physiological one. To this aim and to characterise the type of VGCC present, we analysed intracellular Ca variations during perfusion of oocytes with physiological or depolarising solutions containing different selective inhibitors of VGCC. We also evaluated the effect of their activation or inhibition on oocyte maturation and the pathway involved in transduction of the depolarising stimulus to the oocyte. The results demonstrate that P type VGCC are present on pig oolemma and that their activation by depolarisation produces a prompt a sustained Ca raise able to induce the resumption of oocyte meiotic maturation through the transduction pathway involving the Ca-calmodulin dependent kinase (CaMKII).[...]I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
