Effects of calcium and Bay K-8644 on calcium currents in adrenal medullary chromaffin cells.

The Journal of Membrane Biology
V CeñaE Rojas

Abstract

The kinetic and steady-state characteristics of calcium currents in cultured bovine adrenal chromaffin cells were analyzed by the patch-clamp technique. Whole cell inward Ca2+ currents, recorded in the presence of either 5.2 or 2.6 mM Ca2+ exhibited a single, noninactivating component. To analyze the effects of Ca2+ and Bay K-8644 on the kinetics of the Ca2+ currents, we used a modified version of the Hodgkin-Huxley empirical model. At physiological [Ca2+] (2.5 mM) the midpoint of the steady-state Ca2(+)-channel activation curve lay at -6.9 mV. Increasing the [Ca2+] to 5.2 mM shifted the midpoint by -4.3 mV along the voltage axis. At the midpoint, changes in potential of 7.8 mV (for 5.2 mM Ca2+) and 9.2 mV (for 2.5 mM Ca2+) induced an e-fold change in the activation of the current. Increasing [Ca2+]o from 2.5 to 5.2 mM induced a marked increase in the rate constant for turning on the Ca2+ permeability. Conductances were estimated from the slope of the linear part of the current-voltage relationships as 8.7 and 4.2 nS in the presence of 5.2 and 2.5 mM Ca2+, respectively. Incubation of the cells in the presence of Bay K-8644 at increasing concentrations from 0.001 to 0.1 microM increased the slope conductance from 4.2 to 9.6 nS. ...Continue Reading

References

Jan 1, 1976·Cold Spring Harbor Symposia on Quantitative Biology·E Rojas
Jan 1, 1977·Hormone Research·W J Malaisse, A C Boschero
May 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·S S StojilkovićK J Catt
Jan 1, 1987·Annual Review of Biophysics and Biophysical Chemistry·R W TsienR L Rosenberg
Nov 1, 1989·The American Journal of Physiology·A StutzinE Rojas
Jan 1, 1986·Advances in Experimental Medicine and Biology·H B PollardA L Burns
Sep 1, 1980·Journal of Neurochemistry·D L KilpatrickN Kirshner
Sep 28, 1984·Biochemical and Biophysical Research Communications·F Malaisse-LagaeW J Malaisse
Jan 1, 1982·The Journal of Membrane Biology·M E Quinta-FerreiraN Arispe
Oct 1, 1982·The Journal of Physiology·E M FenwickE Neher
Nov 1, 1983·Pflügers Archiv : European journal of physiology·D C Ogden, D Colquhoun
Apr 1, 1983·The Journal of Physiology·H R Brenner, B Sakmann
Jul 11, 1957·The Journal of Physiology·B FRANKENHAEUSER, A L HODGKIN
Apr 1, 1952·The Journal of Physiology·A L HODGKIN, A F HUXLEY
Mar 3, 1949·The Journal of Physiology·A L HODGKIN, B KATZ

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Citations

May 1, 1995·Pflügers Archiv : European journal of physiology·L GandíaA G García
Jan 1, 1992·Pflügers Archiv : European journal of physiology·C A Doupnik, R Y Pun
May 8, 1993·Biochimica Et Biophysica Acta·C González-GarcíaE Rojas
Jul 22, 1991·Biochimica Et Biophysica Acta·R D Burgoyne
Aug 16, 1994·European Journal of Pharmacology·C MontielA G García
Aug 6, 2000·British Journal of Pharmacology·J JordánV Ceña
Feb 15, 1991·Proceedings of the National Academy of Sciences of the United States of America·M Diverse-PierluissiE W Westhead
May 1, 1993·The Journal of General Physiology·P A SmithC M Fewtrell
Oct 1, 1996·Journal of Autonomic Pharmacology·P M Lundy, R Frew
May 1, 1991·British Journal of Pharmacology·L GandíaA G García
May 12, 2006·Journal of Neurophysiology·Valeria ZampiniSergio Masetto
Apr 13, 1999·The American Journal of Physiology·R Vinet, F F Vargas
Jun 19, 2019·The Journal of Pharmacology and Experimental Therapeutics·Ricardo de PascualAntonio G García

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