Expression of a rapidly inactivating Ca 2+ channel in Pleurodeles oocytes during the resting season

Two kinds of Ca 2+ channel activities have been recorded in unfertilized Pleurodeles oocytes during the resting season: the previously described L-type and a transient one. The transient Ba current (I Ba-t) exhibited a voltage threshold of −36±7 mV, peaked at −18±8 mV and reversed around +50 mV. It...

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Bibliographic Details
Published inFEBS letters Vol. 398; no. 2; pp. 285 - 290
Main Author Ouadid, H.
Format Journal Article
LanguageEnglish
Published Elsevier B.V 02.12.1996
Subjects
Pleurodeles oocyte
Resting season
Transient Ca 2+ channel
Pleurodeles oocyte
Transient Ca 2+ channel
Resting season
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Summary:Two kinds of Ca 2+ channel activities have been recorded in unfertilized Pleurodeles oocytes during the resting season: the previously described L-type and a transient one. The transient Ba current (I Ba-t) exhibited a voltage threshold of −36±7 mV, peaked at −18±8 mV and reversed around +50 mV. It showed a fast monoexponential decay with an inactivation time course of 31.4 ± 1.7 ms at −20 mV. I Ba-t was insensitive to nifedipine and ω-conotoxin-GVIA but blocked by Ni 2+ (50 μM). Moreover, Cd 2+ also reduced I Ba-t but was less efficient thane of Ni 2+. When using Ca 2+ as the charge carrier, the amplitude and the decay of I Ca-t were largely similar to those of I Ba-t. These data demonstrated that the population of Ca 2+ channels could be seasonally modulated in Pleurodeles oocytes.
ISSN:0014-5793
1873-3468
DOI:10.1016/S0014-5793(96)01251-3