scholarly journals Thermodynamic phenomena exhibited in a shortening or lengthening muscle

1924 ◽  
Vol 96 (677) ◽  
pp. 338-348 ◽  
Keyword(s):  
Heat Production ◽  
Quantitative Relation ◽  
Sartorius Muscle ◽  
Heat Measurement

Recently Fenn (1) (2) has investigated the quantitative relation between the energy liberated and the work performed by the isolated sartorius muscle of the frog. He has advanced a qualitative statement of the effect of shortening and lengthening of the muscle on its heat-production, viz., shortening during contraction or lengthening during relaxation produces more heat than the contraction allowed to proceed isometrically, while lengthening during contraction or shortening during relaxation gives out less heat. The present paper deals with a further investigation of this relation. Apparatus and methods. A pair of sartorius muscles of the frog was mounted in the combined thermopile and muscle chamber made by Fenn (1). The method of heat measurement and calibration was essentially the same as that of Hartree and Hill (3); some modification, however, was necessary.

scholarly journals Physical and biochemical energy balance during an isometric tetanus and steady state recovery in frog sartorius at 0 degree C.

1983 ◽  
Vol 81 (3) ◽  
pp. 337-354 ◽  
Author(s):  
R J Paul
Keyword(s):  
Steady State ◽  
Heat Production ◽  
Isometric Force ◽  
Recovery Period ◽  
Lactate Production ◽  
High Energy ◽  
Sartorius Muscle ◽  
State Recovery ◽  
Frog Sartorius ◽  
Initial Heat

Frog sartorius muscle stimulated isometrically for 3 s every 256 s to attain a steady state in which initial heat (QI), recovery heat (QR), rate of O2 consumption (JO2), and isometric force (PO) generated are constant for each cycle. For a 3-s tetanus given every 256 s, JO2 was 0.106 mumol/(min . g blotted weight), approximately 71% of the maximum rate observed, whereas lactate production was negligible under these conditions. QI, QT(= QI + QR), and QT/QI were 88.2, 181.5, 2.06 mJ/g blotted weight, respectively. The high-energy phosphate breakdown (delta approximately P) breakdown during the first 3-s tetanus was not different from that during a contraction in the steady state and averaged 1.1 mumol/g blotted weight. Less than half of the initial heat could be accounted for in terms of the extent of the known chemical reactions occurring during contraction. From the stoichiometry of the theoretical biochemical pathways, the amount of ATP synthesized in the steady state exceeds delta approximately P during contraction by more than twofold, corresponding to an apparent ADP:O ratio of 1.5. If it is assumed that carbohydrate oxidation is the only net chemical reaction in the steady state, the total heat production can be explained on the basis of the measured JO2. Under this assumption, heat production during recovery was less than that expected on the basis of the oxygen consumption and delta approximately P during contraction. These observations support the hypothesis that the unexplained enthalpy production and low apparent ADP:O ratio are causally related, i.e., that the reaction(s) producing the unexplained heat during contraction is reversed during the recovery period.

scholarly journals The relation between initial and recovery heat production in frog's nerve

1933 ◽  
Vol 113 (784) ◽  
pp. 369-386 ◽  
Keyword(s):  
Steady State ◽  
Heat Production ◽  
Short Interval ◽  
Preceding Paper ◽  
Heat Rate ◽  
Recovery Process ◽  
Quantitative Relation ◽  
Rate Of Recovery ◽  
Initial Heat

The latest and best determination of the quantitative relation of the two chief phases of heat production in frog's nerve is that of Bronk (1931) who found the average ratio of total to initial heat to be 11. More recently Hill (1932) has given reason to believe that even Bronk's ratio is probably too low, and in the same paper (p. 148) has suggested an alternative method of estimating it based on the principle of the steady state. the present work arose from this suggestion and has led to the discovery of the profound effect of steady activity on the “efficiency” of the recovery process. The steady state of nerve activity during continual stimulation has been discussed in a preceding paper. Its nature is such that the rate of recovery heat production at any moment corresponds to the rate of initial heat production at that moment. the total heat rate can easily be measured. The initial heat rate can be determined by omitting the stimulus for a short interval, when an analysis of the resulting defection allows an estimate of the heat which immediately drops out as a result of omitting the stimulus, i. e ., of the initial heat.

scholarly journals The absolute value of the isometric heat coefficient TI/H in a muscle twitch, and the effect of stimulation and fatigue

1928 ◽  
Vol 103 (723) ◽  
pp. 163-170 ◽  
Keyword(s):  
Lactic Acid ◽  
Heat Production ◽  
Muscle Length ◽  
Mean Value ◽  
Sartorius Muscle ◽  
Muscle Twitch ◽  
Absolute Value ◽  
The Subject ◽  
The Absolute ◽  
Initial Heat

It is not technically possible to determine directly the lactic acid set free in a sing1e muscle twitch. It is necessary to calculate it from the initial heat production, or from the tension developed. The anaerobic liberation of 1 gramme of lactic acid in musc1e is accompanied, according to Meyerhof, by the production of 385 calories of heat (1). This 1eads to the equation:- 1 gramme-cm.(heat) ≡ 6·14 × 10 -8 gramme lactic acid. (I) The isometric coefficient of lactic acid, defined for a twitch or a series of twitches by the equation* K m =(grammes tension developed) (cms. muscle length)/(grammes lactic acid produced), has been the subject of much investigations by meyerhof and his colleagues (2, 3, 4, 5). Matsuoka, for the frog's sartorius muscle in Ringer's solutions, found a mean value of 1·05 × 10 8 (variation 0·69 to 1·36). Meyerhof and Lohmann, for frog's gastrocnemius, gave 1·40 × 10 8 as a mean, while Meyerhof and Suchulz gave 1·43 × 10 8 (variation 1·12 to 1·66). In the gastrocnemius, however, the fibres are not straight, and do not run parallel to the muscle length; consequently it is necessary to mutiply (see Mashino(6), A. V. Hill(7)) the value so found by a factor of roughly 0·63 to allow for the skew disposition of the fibres. This gives, when corrected, 0·9 × 10 8 for the gastrocnemius, so that taking account of the value 1·05 × 10 8 found by Matsuoka for the sartorius, the round figure 1 × 10 8 may be accepted. This leads to the equation:- 1 gramme-cm.(tension-length) ≡ 10 -8 gramme lactic acid.

scholarly journals Initial Heat Production in Isometric Frog Muscle at 15°C

1973 ◽  
Vol 62 (3) ◽  
pp. 271-285 ◽  
Author(s):  
Allan Fraser ◽  
Francis D. Carlson
Keyword(s):  
Heat Production ◽  
Sarcomere Length ◽  
Heat Rate ◽  
Frog Muscle ◽  
Mechanical Activity ◽  
Sartorius Muscle ◽  
Cooling Phase ◽  
Frog Sartorius ◽  
Initial Heat ◽  
Rest Length

An infrared radiation-detecting system was used to measure initial heat production in bull frog sartorius muscle at 15°C. Numerous tests with the system showed that thermal artifacts were not noticeable. Many previous measurements with myothermic thermopiles were corroborated with this method. In addition, a cooling phase as large as 0.39 of peak exothermicity was found during and after relaxation. Cooling diminished with both increasing sarcomere length and increasing duration of mechanical activity. No large rapid increase in heat rate accompanied a 0.6 reactivation at the peak of twitch tension. Above rest length, initial heat rate and the heat produced up to the peak of tension decreased nearly proportionally with overlap of myofilaments, while the total twitch initial heat decreased slightly.

The Network Parameters Of The T-System In Frog Muscle Measured With The High Voltage Electron Microscope.

1975 ◽  
Vol 33 ◽  
pp. 550-551 ◽  
Author(s):  
Brenda R. Eisenberg ◽  
Lee D. Peachey
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Voltage ◽  
Sartorius Muscle ◽  
High Voltage Electron Microscopy ◽  
Network Parameters ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
T System

Analysis of the electrical properties of the t-system requires knowledge of the geometry of the t-system network. It is now possible to determine the network parameters experimentally by use of high voltage electron microscopy. The t-system was marked with exogenous peroxidase. Conventional methods of electron microscopy were used to fix and embed the sartorius muscle from four frogs. Transverse slices 0.5-1.0 μm thick were viewed at an accelerating voltage of 1000 kV using the JEM-1000 high voltage electron microscope at Boulder, Colorado and prints at x5000 were used for analysis.The length of a t-branch (t) from node to node (Fig. 1a) was measured with a magnifier; at least 150 t-branches around 30 myofibrils were measured from each frog. The mean length of t is 0.90 ± 0.11 μm and the number of branches per myofibril is 5.4 ± 0.2 (mean ± SD, n = 4 frogs).

Sign in / Sign up

Export Citation Format

Share Document