Force regulation by Ca2+ in skinned single cardiac myocytes of frog

Biophysical Journal
P W BrandtC Tesi

Abstract

Atrial and ventricular myocytes 200 to 300 microm long containing one to five myofibrils are isolated from frog hearts. After a cell is caught and held between two suction micropipettes the surface membrane is destroyed by briefly jetting relaxing solution containing 0.05% Triton X-100 on it from a third micropipette. Jetting buffered Ca2+ from other pipettes produces sustained contractions that relax completely on cessation. The pCa/force relationship is determined at 20 degrees C by perfusing a closely spaced sequence of pCa concentrations (pCa = -log[Ca2+]) past the skinned myocyte. At each step in the pCa series quick release of the myocyte length defines the tension baseline and quick restretch allows the kinetics of the return to steady tension to be observed. The pCa/force data fit to the Hill equation for atrial and ventricular myocytes yield, respectively, a pK (curve midpoint) of 5.86 +/- 0.03 (mean +/- SE.; n = 7) and 5.87 +/- 0.02 (n = 18) and an nH (slope) of 4.3 +/- 0.34 and 5.1 +/- 0.35. These slopes are about double those reported previously, suggesting that the cooperativity of Ca2+ activation in frog cardiac myofibrils is as strong as in fast skeletal muscle. The shape of the pCa/force relationship differs fro...Continue Reading

References

Jan 1, 1990·Proceedings of the National Academy of Sciences of the United States of America·H L Sweeney, J T Stull
May 1, 1988·Proceedings of the National Academy of Sciences of the United States of America·B Brenner
Sep 1, 1985·Journal of Molecular and Cellular Cardiology·D G Allen, J C Kentish
Mar 1, 1972·The Journal of General Physiology·P W BrandtH Grundfest
Nov 1, 1970·The Journal of Physiology·R J Podolsky, L E Teichholz
Aug 1, 1980·Pflügers Archiv : European journal of physiology·W G KerrickE H Fischer
Dec 5, 1984·Journal of Molecular Biology·P W BrandtF H Schachat
Aug 1, 1980·Proceedings of the National Academy of Sciences of the United States of America·P W BrandtM Kawai
Aug 1, 1982·The Journal of Physiology·M G Hibberd, B R Jewell
Sep 1, 1995·The American Journal of Physiology·R BottinelliC Reggiani
Aug 1, 1994·Biophysical Journal·W A LinkeG H Pollack
Mar 1, 1994·The Journal of Physiology·F ColomoC Tesi
Apr 1, 1996·Physiological Reviews·S Schiaffino, C Reggiani
Jun 1, 1996·Biophysical Journal·W O HancockA M Gordon

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Citations

Mar 8, 2005·Pflügers Archiv : European journal of physiology·Corrado PoggesiRobert Stehle
Mar 28, 2002·Proceedings of the National Academy of Sciences of the United States of America·James H Marden, Lee R Allen
Apr 23, 2008·Pediatric Research·James J NormanBeth L Pruitt
May 1, 2013·The Journal of Physiology·Alice W RaccaMichael Regnier
Jul 1, 2008·Biophysical Journal·Jeffrey G JacotJeffrey H Omens
Jan 12, 2010·Journal of Molecular and Cellular Cardiology·Robert Stehle, Bogdan Iorga
Nov 3, 2010·Journal of Molecular and Cellular Cardiology·Kareen L KreutzigerMichael Regnier
Jan 30, 2004·Biophysical Journal·Hunter MartinRobert J Barsotti
Aug 7, 2016·Royal Society Open Science·Jean-Pierre Rospars, Nicole Meyer-Vernet
Sep 25, 2017·The Journal of Experimental Biology·Cornelia E FanterDaniel E Warren
Feb 16, 2016·Biochemistry. Biokhimii︠a︡·L V NikitinaS Y Bershitsky
Apr 4, 2000·Physiological Reviews·A M GordonM Regnier
Feb 9, 2002·American Journal of Physiology. Heart and Circulatory Physiology·Juichiro ShimizuDaniel Burkhoff
May 18, 2001·American Journal of Physiology. Heart and Circulatory Physiology·J R PatelR L Moss

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