M. Mattioli et al., CALCIUM AND POTASSIUM CURRENTS IN PORCINE GRANULOSA-CELLS MAINTAINED IN FOLLICULAR OR MONOLAYER TISSUE-CULTURE, The Journal of membrane biology, 134(1), 1993, pp. 75-83
We studied membrane currents in granulosa cells (GC), immediately afte
r collection or after variable culture time in the everted-follicle wa
ll or in the monolayer. GC in both systems express an inward calcium c
urrent (I(Ca)) with T-type kinetics and voltage dependence. GC in the
everted-follicle culture express an outward potassium current (I(K)) k
inetics, which remains unchanged during three days in culture. I(K) ha
s delayed-rectifier kinetics, but is insensitive to TEA, 4-AP and apam
ine. GC in monolayer culture develop a new, inactivating delayed-recti
fier potassium current (I(nK)), which progressively dominates as cells
advance from day one to day three in culture. A similar I(nK) was rec
orded in large luteal cells. A possible link between luteinization and
the appearance of I(nK) is hypothesized.