PT  - JOURNAL ARTICLE
AU  - Nishio, M
AU  - Tsukahara, H
AU  - Hiraoka, M
AU  - Sudo, M
AU  - Kigoshi, S
AU  - Muramatsu, I
TI  - Calcium channel current in cultured rat mesangial cells.
DP  - 1993 Jan 01
TA  - Molecular Pharmacology
PG  - 96--99
VI  - 43
IP  - 1
4099  - http://molpharm.aspetjournals.org/content/43/1/96.short
4100  - http://molpharm.aspetjournals.org/content/43/1/96.full
SO  - Mol Pharmacol1993 Jan 01; 43
AB  - The presence of voltage-dependent calcium channels has been suggested in mesangial cells by using calcium-sensitive fluorescent probes. However, direct electrophysiological evidence for voltage-dependent calcium channels has not yet been presented. In this study voltage-dependent calcium channels were studied in cultured rat mesangial cells. Whole-cell patch-clamp experiments were done with 50 mM Ba2+ as a charge carrier. Step depolarizing pulses from a holding potential of -50 mV produced an inward barium current at potentials more positive than -10 mV, and a peak current (10-45 pA) was obtained at a membrane potential of approximately +30 mV. The inward current was augmented by 100 nM Bay K 8644, attenuated by 1 microM nifedipine, and abolished by 50 microM Cd2+. These results indicate that the inward current is a barium current flowing through L-type calcium channels. This may be the first study that demonstrates the presence of L-type calcium channels in mesangial cells.