Electrical and mechanical responses from ventricular muscle fibers after inactivation of the sodium carrying system

1970 ◽  
Vol 317 (4) ◽  
pp. 359-372 ◽  
Author(s):  
D. Mascher
Keyword(s):  
Muscle Fibers ◽  
Ventricular Muscle ◽  
Mechanical Responses

A mathematical model of mechanical responses of contracting muscle fibers to temperature jumps

BIOPHYSICS ◽  
2009 ◽  
Vol 54 (4) ◽  
pp. 525-530
Author(s):  
N. A. Koubassova ◽  
S. Yu. Bershitsky ◽  
A. K. Tsaturyan
Keyword(s):  
Mathematical Model ◽  
Muscle Fibers ◽  
Contracting Muscle ◽  
Mechanical Responses ◽  
Temperature Jumps

Toxic effects of ouabain on Purkinje fibers and ventricular muscle fibers

1962 ◽  
Vol 203 (3) ◽  
pp. 433-439 ◽  
Author(s):  
Mario Vassalle ◽  
Johannes Karis ◽  
Brian F. Hoffman
Keyword(s):  
Muscle Fibers ◽  
Toxic Effects ◽  
Resting Potential ◽  
Ventricular Muscle ◽  
Purkinje Fibers ◽  
Diastolic Depolarization ◽  
Series Of Experiments ◽  
Time Required ◽  
Induced Changes

Toxic effects of ouabain on single Purkinje fibers and ventricular muscle fibers were investigated in vitro by microelectrode technique. Toxicity developed much earlier in the specialized conducting fibers and consisted of a progressively increasing rate of diastolic depolarization and a decrease of amplitude and duration of the action potential. The majority of Purkinje fiber preparations developed extrasystoles and rapid spontaneous rhythms. The resting potential was much decreased. The ouabain-induced changes in ventricular muscle fibers occurred much later than did changes in Purkinje fibers and consisted of a decrease in the plateau and in the amplitude of the action and resting potential. Spontaneous depolarization was not observed in muscle fibers. The effect of the rate of stimulation on the development of ouabain toxicity was studied in another series of experiments on driven and quiescent muscles. Signs of toxicity appeared earlier in the driven muscles than in duplicate quiescent muscles and, at faster rates of stimulation, the time required for the toxic changes was shortened.

scholarly journals Myosin types and fiber types in cardiac muscle. I. Ventricular myocardium.

1981 ◽  
Vol 88 (1) ◽  
pp. 226-233 ◽  
Author(s):  
S Sartore ◽  
L Gorza ◽  
S Pierobon Bormioli ◽  
L Dalla Libera ◽  
S Schiaffino
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Cardiac Muscle ◽  
Muscle Fibers ◽  
Ventricular Myocardium ◽  
Rabbit Heart ◽  
Fiber Types ◽  
Ventricular Muscle ◽  
The Right ◽  
Atrial Myosin

Antisera against bovine atrial myosin were raised in rabbits, purified by affinity chromatography, and absorbed with insolubilized ventricular myosin. Specific anti-bovine atrial myosin (anti-bAm) antibodies reacted selectively with atrial myosin heavy chains, as determined by enzyme immunoassay combined with SDS-gel electrophoresis. In direct and indirect immunofluorescence assay, anti-bAm was found to stain all atrial muscle fibers and a minor proportion of ventricular muscle fibers in the right ventricle of the bovine heart. In contrast, almost all muscle fibers in the left ventricle were unreactive. Purkinje fibers showed variable reactivity. In the rabbit heart, all atrial muscle fibers were stained by anti-bAm, whereas ventricular fibers showed a variable response in both the right and left ventricle, with a tendency for reactive fibers to be more numerous in the right ventricle and in subepicardial regions. Diversification of fiber types with respect to anti-bAm reactivity was found to occur during late stages of postnatal development in the rabbit heart and to be influenced by thyroid hormone. All ventricular muscle fibers became strongly reactive after thyroxine treatment, whereas they became unreactive or poorly reactive after propylthiouracil treatment. These findings are consistent with the existence of different ventricular isomyosins whose relative proportions can vary according to the thyroid state. Variations in ventricular isomyosin composition can account for the changes in myosin Ca2+-activated ATPase activity previously observed in cardiac muscle from hyper- and hypothyroid animals and may be responsible for the changes in the velocity of contraction of ventricular myocardium that occur under these conditions. The differential distribution of ventricular isomyosins in the normal heart suggests that fiber types with different contractile properties may coexist in the ventricular myocardium.

scholarly journals Oscillatory afterpotentials in dog ventricular muscle fibers.

1981 ◽  
Vol 48 (4) ◽  
pp. 510-518 ◽  
Author(s):  
M Hiraoka ◽  
Y Okamoto ◽  
T Sano
Keyword(s):  
Muscle Fibers ◽  
Ventricular Muscle
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