Stretch‐activation of rat cardiac myocytes

Mechanically activated ion channels (MACs) in rat ventricular myocytes were activated by stretching membrane patches attached to microelectrodes. Charge injection from MACs, consisting mainly of inward K+, was sometimes of sufficient magnitude (0.2 pC) during brief (50 ms) periods, to trigger action currents. Action currents were shown to be extracellular records of action potentials. These results demonstrate the activation of myocytes by injection of approximately 4 pA from a few MACs in a membrane patch.

[1]  B. Hoffman,et al.  Effects of stretch on mechanical and electrical properties of cardiac muscle , 1963 .

[2]  J. Cowan,et al.  Contraction-excitation feedback in an ejecting whole heart model--dependence of action potential duration on left ventricular diastolic and systolic pressures. , 1991, Cardiovascular research.

[3]  M J Lab,et al.  Contraction-excitation feedback in myocardium. Physiological basis and clinical relevance. , 1982, Circulation research.

[4]  D E Hansen,et al.  Stretch-induced depolarizations as a trigger of arrhythmias in isolated canine left ventricles. , 1992, The American journal of physiology.

[5]  D. Kass,et al.  Electrophysiological effect of varied rate and extent of acute in vivo left ventricular load increase. , 1991, Cardiovascular research.

[6]  William Craelius,et al.  Stretch activated ion channels in ventricular myocytes , 1988, Bioscience reports.

[7]  M R Franz,et al.  Mechanically induced action potential changes and arrhythmia in isolated and in situ canine hearts. , 1989, Cardiovascular research.

[8]  P. H. Barry,et al.  Action potentials initiated by single channels opening in a small neuron (rat olfactory receptor). , 1989, Biophysical journal.

[9]  T. Streubel,et al.  Mechanosensitive cells in the atrium of frog heart , 1992, Experimental physiology.

[10]  L. Hondeghem,et al.  Stretch-induced arrhythmias in the isolated canine ventricle. Evidence for the importance of mechanoelectrical feedback. , 1990, Circulation.

[11]  F. Eberli,et al.  A single myocardial stretch or decreased systolic fiber shortening stimulates the expression of heat shock protein 70 in the isolated, erythrocyte-perfused rabbit heart. , 1991, The Journal of clinical investigation.

[12]  J Y Le Guennec,et al.  Stretch‐induced increase of resting intracellular calcium concentration in single guinea‐pig ventricular myocytes , 1991, Experimental physiology.

[13]  B. Hille.  Ionic selectivity of Na and K channels of nerve membranes. , 1975, Membranes.

[14]  Fred J. Sigworth,et al.  An Example of Analysis , 1983 .

[15]  F. Sachs,et al.  Block of stretch-activated ion channels in Xenopus oocytes by gadolinium and calcium ions. , 1989, Science.

[16]  G. Cooper,et al.  Load Responsiveness of Protein Synthesis in Adult Mammalian Myocardium: Role of Cardiac Deformation Linked to Sodium Influx , 1989, Circulation research.

[17]  R. Anderson,et al.  Electrophysiological effects of transient aortic occlusion in intact canine heart. , 1985, The American journal of physiology.

[18]  M. Boutjdir,et al.  Early Afterdepolarizations and Arrhythmogenesis , 1990 .

[19]  D E Hansen,et al.  Dose-dependent inhibition of stretch-induced arrhythmias by gadolinium in isolated canine ventricles. Evidence for a unique mode of antiarrhythmic action. , 1991, Circulation research.

[20]  D. Hansen,et al.  Stretch-induced arrhythmias in isolated, canine ventricle , 1990 .

[21]  J. Troquet,et al.  Intracellular action potential changes induced in both ventricles of the rat by an acute right ventricular pressure overload. , 1980, Cardiovascular research.

[22]  R. Dehaan,et al.  Channel currents during spontaneous action potentials in embryonic chick heart cells. The action potential patch clamp. , 1984, Biophysical journal.