Biophysical Journal 49: 1237-1242 (1986)
© 1986 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Caffrey, J M Articles by Brown, A M Search for Related Content PubMed PubMed Citation Articles by Caffrey, J M Articles by Brown, A M

Calcium channels of amphibian stomach and mammalian aorta smooth muscle cells.

ABSTRACT

Whole-cell and single-channel calcium currents were studied using single smooth muscle cells enzymatically-isolated from stomach of Amphiuma tridactylum and from guinea-pig aorta. These cells have a high specific resistance and can sustain calcium action potentials after suppression of potassium currents. Dialyzed Amphiuma smooth muscle cells had calcium currents which were stable for several hours whereas the calcium currents of aortic cells ran down quickly. Single channel calcium currents in cell-attached patches behaved similarly for the two cell types. Calcium channel conductance in 110 mM barium was 12 pS and the mean open time was 1.4 ms at a nominal membrane potential of +10 mV. Exposure of both cell types to BAY K8644 resulted in a dramatic prolongation of the calcium channel open times and a shift in the probability of opening to more negative potentials. Low-threshold calcium channels were not identified in the extensively studied amphibian cells. High-threshold calcium channels therefore appear to be the primary pathway for the calcium influx that produces contraction in these smooth muscle cells.

This article has been cited by other articles:

				X. Wang, T. A. Ponoran, R. L. Rasmusson, D. S. Ragsdale, and B. Z. Peterson Amino Acid Substitutions in the Pore of the CaV1.2 Calcium Channel Reduce Barium Currents without Affecting Calcium Currents Biophys. J., September 1, 2005; 89(3): 1731 - 1743. [Abstract] [Full Text] [PDF]

				S. I. McDonough, Y. Mori, and B. P. Bean FPL 64176 Modification of CaV1.2 L-Type Calcium Channels: Dissociation of Effects on Ionic Current and Gating Current Biophys. J., January 1, 2005; 88(1): 211 - 223. [Abstract] [Full Text] [PDF]

				I. R. Josephson, A. Guia, E. G. Lakatta, and M. D. Stern Modulation of the Conductance of Unitary Cardiac L-Type Ca2+ Channels by Conditioning Voltage and Divalent Ions Biophys. J., November 1, 2002; 83(5): 2587 - 2594. [Abstract] [Full Text] [PDF]

				H. KURIYAMA, K. KITAMURA, T. ITOH, and R. INOUE Physiological Features of Visceral Smooth Muscle Cells, With Special Reference to Receptors and Ion Channels Physiol Rev, July 1, 1998; 78(3): 811 - 920. [Abstract] [Full Text] [PDF]

				J. Caffrey, A. Brown, and M. Schneider Mitogens and oncogenes can block the induction of specific voltage-gated ion channels Science, May 1, 1987; 236(4801): 570 - 573. [Abstract] [PDF]

				R. Miller Multiple calcium channels and neuronal function Science, January 2, 1987; 235(4784): 46 - 52. [Abstract] [PDF]