RT Journal Article
SR Electronic
T1 Calcium channel current in cultured rat mesangial cells.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 96
OP 99
VO 43
IS 1
A1 Nishio, M
A1 Tsukahara, H
A1 Hiraoka, M
A1 Sudo, M
A1 Kigoshi, S
A1 Muramatsu, I
YR 1993
UL http://molpharm.aspetjournals.org/content/43/1/96.abstract
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.