scholarly journals IN SITU PAPILLARY MUSCLE PREPARATION AND SOME BASIC CONTRACTILE PROPERTIES

1975 ◽  
Vol 25 (5) ◽  
pp. 659-664
Author(s):  
Hiroyuki SUGA ◽  
Yoshinobu NUMAO
Keyword(s):  
Papillary Muscle ◽  
Contractile Properties ◽  
Muscle Preparation

An energy density function for papillary muscle encompassing both elastic and contractile properties

1981 ◽  
Vol 52 (5) ◽  
pp. 3674-3687 ◽  
Author(s):  
Willem Klip ◽  
Lloyd L. Hefner ◽  
Thomas C. Donald ◽  
David N. S. Reeves ◽  
Jane B. Hazelrig ◽  
...  
Keyword(s):  
Energy Density ◽  
Density Function ◽  
Papillary Muscle ◽  
Contractile Properties

Functional significance of compensatory overloaded rat fast muscle

1982 ◽  
Vol 52 (2) ◽  
pp. 473-478 ◽  
Author(s):  
R. R. Roy ◽  
I. D. Meadows ◽  
K. M. Baldwin ◽  
V. R. Edgerton
Keyword(s):  
Biochemical Properties ◽  
Slow Muscle ◽  
Repetitive Stimulation ◽  
Contractile Properties ◽  
Sectional Area ◽  
Shortening Velocity ◽  
Cross Sectional ◽  
Time To Peak ◽  
Isometric Twitch

Chronic overload of a skeletal muscle by removing its synergists produces hypertrophy and marked changes in its metabolic and biochemical properties. In this study alterations in the contractile properties of the plantaris 12–14 wk after bilateral removal of the soleus and gastrocnemius were investigated. In situ isometric and isotonic contractile properties of overloaded plantaris (OP), normal plantaris (NP), and normal soleus (NS) were tested at 33 +/- 1 degree C. Op were 97% heavier than NP and produced 43 and 46% higher twitch (Pt) and tetanic (Po) tensions. However, NP produced more tension per cross-sectional area than OP (mean 26.2 vs. 21.6 N/cm2; P less than 0.001). Isometric twitch time to peak tension (TPT) and half-relaxation time (1/2RT) were significantly longer in OP (mean 36.4 vs. 32.5 ms and 23.9 vs. 18.4 ms). Mean maximum shortening velocity (Vmax, mm/s per 1,000 sarcomeres) were 34.1 for NP and 18.1 for OP (P less than 0.001). The degree of conversion toward the Vmax of NS was 74% compared with only 19 and 14% for TPT and 1/2RT. OP produced a higher proportion of Po at a given stimulation frequency than NP and showed less fatigue than NP after repetitive stimulation. Chronic overload of the fast plantaris modified to varying degrees the contractile properties studied toward that resembling a slow muscle. Although the maximum tension of OP was markedly enhanced it was not in proportion to the increase in muscle mass.

Effects of vigorous isometric muscle contraction on titin stiffness-related contractile properties in rat fast-twitch muscles

2021 ◽  
Author(s):  
Jiayu Shi ◽  
Daiki Watanabe ◽  
Masanobu Wada
Keyword(s):  
Protein Kinase ◽  
Contractile Properties ◽  
Isometric Contractions ◽  
Passive Force ◽  
Isometric Muscle Contraction ◽  
Protein Kinase Cα ◽  
Gastrocnemius Muscles ◽  
Initial Force ◽  
Fast Twitch

This study was conducted to examine the effects of an acute bout of vigorous isometric contractions on titin stiffness-related contractile properties in rat fast-twitch skeletal muscles. Intact gastrocnemius muscles were electrically stimulated in situ until the force was reduced to ~50% of the initial force. Immediately after cessation of the stimulation, the superficial regions of the muscles were dissected and subjected to biochemical and skinned fiber analyses. The stimulation resulted in a decrease in the titin-based passive force. The amounts of fragmented titin were unchanged by the stimulation. Protein kinase Cα-treatment increased the passive force in stimulated fibers to resting levels. The stimulation had no effect on the maximum Ca2+-activated force (max Ca2+ force) at a sarcomere length (SL) of 2.4 μm and decreased myofibrillar (my)-Ca2+ sensitivity at 2.6-μm SL. Stretching the SL to 3.0 μm led to the augmentation of the max Ca2+ force and my-Ca2+ sensitivity in both rested and stimulated fibers. For the max Ca2+ force, the extent of the increase was smaller in stimulated than in rested fibers, whereas for my-Ca2+ sensitivity, it was higher in stimulated than in rested fibers. These results suggest that vigorous isometric contractions decrease the titin-based passive force, possibly because of a reduction in phosphorylation by protein kinase Cα, and that the decreased titin stiffness may contribute, at least in part, to muscle fatigue.

scholarly journals Procedures for Rat in situ Skeletal Muscle Contractile Properties

10.3791/3167 ◽  
2011 ◽  
Author(s):  
Brian R. MacIntosh ◽  
Shane P. Esau ◽  
R. John Holash ◽  
Jared R. Fletcher
Keyword(s):  
Skeletal Muscle ◽  
Contractile Properties ◽  
Muscle Contractile Properties ◽  
Muscle Contractile

Convenient apparatus for recording contractions of isolated heart muscle

1965 ◽  
Vol 20 (4) ◽  
pp. 755-757 ◽  
Author(s):  
John R. Blinks
Keyword(s):  
Papillary Muscle ◽  
Heart Muscle ◽  
Isolated Heart ◽  
Organ Bath ◽  
Muscle Preparation ◽  
Isolated Atria ◽  
Double Muscle ◽  
Stimulating Electrodes ◽  
Chronotropic Effects ◽  
Isolated Organ Bath

A simple and convenient apparatus for physiological or pharmacological experiments on preparations of isolated heart muscle is described. Provision is made for recording independently from two preparations mounted in the same bath. Electrodes for stimulation or recording are incorporated in the clamps that hold the tissue. The construction ensures the maintenance of a high oxygen tension at the surface of the tissue without the mechanical artifacts that result from bubbling oxygen directly past it. papillary muscle; isolated organ bath; isolated atria; double muscle preparation; circulating salt solution; stimulating electrodes; concentration-effect curves; inotropic and chronotropic effects; oxygenation Submitted on November 5, 1964

Accurate assessment of in situ isometric contractile properties of hindlimb plantar and dorsal flexor muscle complex of intact mice

2000 ◽  
Vol 439 (5) ◽  
pp. 665-670 ◽  
Author(s):  
M. Gorselink ◽  
M.R. Drost ◽  
J. de Louw ◽  
P.J.B. Willems ◽  
N. Rosielle ◽  
...  
Keyword(s):  
Contractile Properties ◽  
Accurate Assessment ◽  
Flexor Muscle ◽  
Muscle Complex
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