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Daniela Platano, M. Cristina Magli, Anna Pia Ferraretti, Luca Gianaroli, Giorgio Aicardi, L- and T-Type Voltage-Gated Ca2+ Channels in Human Granulosa Cells: Functional Characterization and Cholinergic Regulation, The Journal of Clinical Endocrinology & Metabolism, Volume 90, Issue 4, 1 April 2005, Pages 2192–2197, https://doi.org/10.1210/jc.2004-1819
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Abstract
Using the whole-cell configuration of the patch-clamp technique, we have characterized two types of ionic currents through voltage-dependent Ca2+ channels in human granulosa cells. One is long-lasting, activates at approximately −20 mV, reaches the peak at approximately +20 mV, has an inactivation time constant of 132.5 ± 5.6 msec at 20 mV, and is sensitive to dihydropyridines. The other is transient, activates at approximately −40 mV, peaks at approximately −10 mV, has an inactivation time constant of 38.8 ± 1.8 msec at −10 mV, displays a voltage-dependent inactivation, and is sensitive to 100 μm Ni2+, but not to dihydropyridines. Biophysical and pharmacological properties of these currents indicate that they are gated through L- and T-type calcium channels, respectively. The cholinergic receptor agonist carbachol (50 μm) reduces the amplitude of the currents through both L-type (−34.7 ± 6.4%; n = 10) and T-type (−52.6 ± 7.4%; n = 8) channels, suggesting a possible role of these channels in the cholinergic regulation of human ovarian functions.
