scholarly journals STUDIES ON THE RIGOR RESULTING FROM THE THAWING OF FROZEN FROG SARTORIUS MUSCLE

1950 ◽  
Vol 33 (5) ◽  
pp. 563-577 ◽  
Author(s):  
S. V. Perry
Keyword(s):  
Hydrogen Peroxide ◽  
Iodoacetic Acid ◽  
Sartorius Muscle ◽  
Fixed Length ◽  
Frog Sartorius Muscle ◽  
Vitro Effect ◽  
Resting Muscle ◽  
Frog Sartorius

1. The rigor which takes place when completely frozen frog sartorius muscle is thawed ("thaw rigor"), is accompanied by a decrease in length of 70 per cent and a loss in weight of 35 per cent, whether the muscle is frozen in the resting or the exhausted condition, or during isometric tetanus. Muscle tetanized to maximal shortening shows a loss in weight of 25 per cent on thawing. 2. A load of 8 gm. is sufficient to prevent the decrease in length on thawing, but after its removal the muscle will shorten almost to the normal extent. 3. Inhibitors such as azide, cyanide, 2:4 dinitrophenol, p-chloromercuribenzoate, Cu, and hydrogen peroxide, when used for periods not exceeding 1 hour, have little effect on the shortening; although in some cases these poisons render the muscle inexcitable. 4. Muscles poisoned with iodoacetic acid and stimulated to exhaustion, or maintained at fixed length in nitrogen, show little or no shortening on thawing. ATP can produce shortening in the muscles in which it has been prevented. 5. The phenomenon is considered to be due to an in situ synaeresis of the actomyosin of the myofibrils. As a result of the disorganisation of the muscle protoplasm produced by the freezing and subsequent thawing, the ATP, which must be bound or localized in the resting muscle, can act on the myofibril in a similar manner to its in vitro effect on the actomyosin thread.

scholarly journals The Meyerhof quotient and the synthesis of glycogen from lactate in frog and rabbit muscle. A reinvestigation

1970 ◽  
Vol 118 (5) ◽  
pp. 887-893 ◽  
Author(s):  
J. R. Bendall ◽  
A. A. Taylor
Keyword(s):  
Liquid Paraffin ◽  
Psoas Muscle ◽  
Co2 Concentration ◽  
Sartorius Muscle ◽  
Rabbit Muscle ◽  
Bathing Medium ◽  
Frog Sartorius Muscle ◽  
Muscle Ph ◽  
Resting Muscle ◽  
Frog Sartorius

1. The conversion of lactate into glycogen was demonstrated in frog sartorius muscle in oxygen. The rates and amounts are highest when lactate is added to the bathing medium and are dependent on lactate and CO2 concentration, as well as pH. The glycogen content of a resting muscle can be doubled in 4h at 24°C. 2. Sartorius muscle, recovering aerobically in liquid paraffin from a period of anoxia, converts preformed lactate into glycogen at a lower rate and in smaller amounts than when lactate is added in an aqueous medium. The lower rates are similar to those Meyerhof found under the same conditions, after correction for temperature; they can be attributed partly to low muscle pH and partly to the limited amounts of lactate present. 3. Rabbit psoas muscle also shows the ability to convert added lactate into glycogen under aerobic conditions. The rates are low and similar to those in frog sartorius muscle recovering from anoxia. 4. The present experiments yield a Meyerhof quotient of 6.2, compared with Meyerhof's value of 4–5. However, these values are not significantly different from one another. 5. It is suggested that the glycogen coefficient, i.e. mol of glycogen formed/mol of lactate disappearing, is a more reliable way of assessing the resynthetic mechanism than the original quotient, i.e. mol of lactate disappearing/mol of lactate oxidized. The found coefficient is 0.419±0.024.

Effect of stretch on O2 consumption of resting and active frog sartorius muscle

1962 ◽  
Vol 203 (4) ◽  
pp. 731-734 ◽  
Author(s):  
W. J. Whalen ◽  
L. C. Collins ◽  
H. Berry
Keyword(s):  
Oxygen Consumption ◽  
Heart Muscle ◽  
Heat Liberation ◽  
Sartorius Muscle ◽  
O2 Consumption ◽  
Frog Sartorius Muscle ◽  
Resting Tension ◽  
Resting Muscle ◽  
Frog Sartorius

Oxygen consumption and resting and developed tension were measured simultaneously while the length of the muscle was increased by known increments. The Qo2 of resting muscle increased about 1% for each 1% extension beyond the relaxed length. Both resting tension and length were directly related to Qo2. In a stimulated muscle, Qo2 and frequency of contraction showed a highly significant correlation. The Qo2 of a stimulated muscle increased as the length and total tension (developed plus resting) increased. Neither Qo2 nor the increment in Qo2 above the resting level correlated significantly with developed tension. These latter findings differ from the results predicted from heat-liberation experiments. The results found here are not markedly different from those we found in heart muscle.

AMP deaminase binding in contracting rat skeletal muscle

1992 ◽  
Vol 263 (2) ◽  
pp. C287-C293 ◽  
Author(s):  
K. W. Rundell ◽  
P. C. Tullson ◽  
R. L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Iodoacetic Acid ◽  
Amp Deaminase ◽  
Energy Demands ◽  
Slow Twitch Muscle ◽  
Fast Twitch ◽  
Resting Muscle

AMP deaminase, which hydrolyses AMP to inosine 5'-monophosphate (IMP) and NH3 at high rates during excessive energy demands in skeletal muscle, is activated when bound to myosin in vitro. We evaluated AMP deaminase binding in vivo during muscle contractions to assess whether binding 1) is inherent to deamination and found only with high rates of IMP production or simply coincident with the contractile process and 2) requires cellular acidosis. AMP deaminase activity (mumol.min-1.g-1) was measured in the supernatant (free) and 10(4)-g pellet (bound) homogenate fractions of muscle of anesthetized rats after in situ contractions to determine the percent bound. In resting muscle, nearly all (approximately 90%) AMP deaminase is free (cytosolic). During contractions when energy balance was well maintained, binding did not significantly differ from resting values. However, during intense contraction conditions that lead to increased IMP concentration, binding increased to approximately 60% (P less than 0.001) in fast-twitch and approximately 50% in slow-twitch muscle. Binding increased in an apparent first-order manner and preceded initiation of IMP formation. Further, binding rapidly declined within 1 min after cessation of intense stimulation, even though the cell remained extremely acidotic. Extensive binding during contractions was also evident without cellular acidosis (iodoacetic acid-treated muscle). Thus the in vivo AMP deaminase-myosin complex association/dissociation is not coupled to changes in cellular acidosis. Interestingly, binding remained elevated after contractions, if energy recovery was limited by ischemia. Our results are consistent with myosin binding having a role in AMP deaminase activation and subsequent IMP formation in contracting muscle.

Constancy of Axial Spacings in Frog Sartorius Muscle during Contraction

Nature ◽  
1965 ◽  
Vol 206 (4991) ◽  
pp. 1358-1358 ◽  
Author(s):  
H. E. HUXLEY ◽  
W. BROWN ◽  
K. C. HOLMES
Keyword(s):  
Sartorius Muscle ◽  
Frog Sartorius Muscle ◽  
Frog Sartorius
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