The effects of EMD 57033 on rigor tension in porcine skinned cardiac trabecula

The superficial red muscle of lingcod (Ophiodon elongatus) was shown to exhibit unique properties of post-mortem contraction and tension development. In comparison with white muscle, rigor contraction and isometric rigor tension in red muscle were about three times as great. The rate of contraction of the red muscle was dependent on temperature and also on the oxygen concentration in the surrounding atmosphere. The elastic modulus of the red muscle of trout and lingcod increased with increasing post-mortem time. Following the onset of rigor mortis a gradual increase in elasticity was observed. The maximum effects of contraction, tension and elasticity coincided with the onset of rigor mortis and each could therefore be used as a measure of this phenomenon. It was concluded from these experiments that stiffening of a fish with the onset of rigor mortis is not due to contraction or tension development of the muscles, but rather to their changing mechanical properties. A convenient measure of the changing mechanical properties in the muscle was the elastic modulus.Morphological differences between the very active, myoglobin rich, red muscle and the white muscle of lingcod were demonstrated by means of electron micrographs. The high glycogen content in the area of sarcoplasm of the red muscle, as indicated in electron micrographs, was confirmed by chemical analysis. Red muscle in rested fish was shown to contain from 1 to 3 times more glycogen than white muscle.

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Creatine kinase in regulation of heart function and metabolism. II. The effect of phosphocreatine on the rigor tension of EGTA-treated rat myocardial fibers

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research ◽

10.1016/0167-4889(84)90116-2 ◽

1984 ◽

Vol 803 (4) ◽

pp. 265-270 ◽

Cited By ~ 22

Author(s):

Vladimir I. Veksler ◽

Valery I. Kapelko

Keyword(s):

Creatine Kinase ◽

Heart Function ◽

Rigor Tension ◽

Myocardial Fibers

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Increase in resting tension of tracheal muscle due to rigor during metabolic inhibition

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1976.231.5.1470 ◽

1976 ◽

Vol 231 (5) ◽

pp. 1470-1475 ◽

Cited By ~ 15

Author(s):

D Bose

Keyword(s):

Smooth Muscle ◽

Creatine Phosphate ◽

Metabolic Inhibition ◽

Muscle Stiffness ◽

Bathing Medium ◽

Similar Treatment ◽

Resting Tension ◽

Small Load ◽

Tissue Calcium ◽

Rigor Tension

Resting tension of canine tracheal smooth muscle increased when glucose and oxygen were withdrawn from the bathing medium. Similar treatment of muscle stimulated with carbachol caused first a relaxation and then a secondary increase in tension. The increase in tension due t0 metabolic inhibition, unlike normal tracheal contractions, was insensitive to calcium depletion, was not associated with an active state, and was accompanied by marked reduction of tissue adenosine triphosphate, creatine phosphate, and glycogen content. Because muscle stiffness was also increased we concluded that hypoxic glucose-free contracture is due to rigor and not to an increased tissue calcium level as has been previously suggested. Rigor shortening during lightly loaded isotonic conditions is better maintained than rigor tension during isometric conditions. Our results also indicate that rigor tension is reduced irreversibly on imposition of a load and, therefore, the load-extension relationship during rigor in smooth muscle should be studied by making only small load changes.

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The dependence of rigor tension on sarcomere length in vertebrate muscle

Cellular and Molecular Life Sciences ◽

10.1007/bf01938995 ◽

1974 ◽

Vol 30 (9) ◽

pp. 1036-1038 ◽

Cited By ~ 5

Author(s):

P. A. McGrath ◽

C. G. Dos Remedios

Keyword(s):

Sarcomere Length ◽

Vertebrate Muscle ◽

Rigor Tension

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“Anti-rigor” cross bridges may reflect altered state of actin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159941 ◽

1990 ◽

Vol 48 (3) ◽

pp. 480-481

Author(s):

Károly Trombitás ◽

Gerald H. Pollack

Keyword(s):

Fiber Length ◽

Flight Muscle ◽

Insect Flight ◽

Altered State ◽

Insect Flight Muscle ◽

Rigor Tension ◽

Cross Bridges ◽

Regular Manner ◽

Triton X ◽

Muscle Myosin

We reported earlier that in insect flight muscle, myosin heads could form either rigor bridges or “anti-rigor” bridges, with reversed angle. When rigor develops at constant fiber length, the bridge angle is typically 45°—the rigor bridge. When rigor develops isotonically, so that the specimen can shorten, regularly arranged anti-rigor bridges are also observed.To investigate anti-rigor bridges further, bumblebee-ilight muscle fibers were prepared as described previously. Fresh fiber samples were stretched to 5-15% beyond their natural length, and then chemically skinned by a two-hour soak in a relaxing solution containing 0.5% Triton X-100. The stretched muscles were then alternately transferred and kept for 20 minutes in relaxing and rigor solutions until some of the fibers broke as a result of the developing rigor tension. Samples were then fixed in rigor, and the broken fibers were separated from the intact fibers.Micrographs of the intact fibers revealed the conventional rigor-bridge angles (Figure. 1). “Chevrons” formed by bridge pairs pointed away from the Z-line in a regular manner.

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