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.

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 Recovery heat in muscle

1939 ◽  
Vol 127 (848) ◽  
pp. 297-307 ◽  
Keyword(s):  
Steady State ◽  
Heat Production ◽  
Resting Metabolic Rate ◽  
Heat Rate ◽  
Base Line ◽  
Large Increment ◽  
Prolonged Heat ◽  
Resting Muscle ◽  
Initial Heat ◽  
Half Minute

It has been suggested (Sacks 1938, p. 222) “that the post-stimulation heat (in muscle) merely represents the inertia of the tissue in returning to the resting metabolic level after a burst activity.” It is true that the recovery heat after a single contraction , as ordinary observed, would not mean a very large increment in the resting metabolic rate, and that for single contractions it can be accurately measured only by assuming the resting heat rate as a constant base-line. Single contractions, however, have not provided the only, or indeed the strongest, evidence for the existence of the recovery heat; for example: (i) Hill (1928 a , p. 188) showed that if oxygen is admitted to a muscle previously stimulated in nitrogen a large and prolonged heat production occurs: this experiment is regularly given as a class demonstration in this laboratory; (ii) Hill (1928 a , p. 185) showed that during and after a long regular series of twiches the heat production in oxygen is considerably, not slighlty, greater than it is nitrogen; (iii) Bugnard (1934) examined the relation between total heat and initial heat during the steady state due to a regular series of shocks in oxygen. The recovery heat, as usual, was about equal to the initial heat. Its accumulated rate, however, was high, not low as after a single contraction. An amount of recovery heat equal to the initial heat occurred every half minute (the interval between shocks) throughtout the steady state. The heat rate during the interval between two shocks was about three times that of the resting muscle.

scholarly journals The absence of delayed anaerobic heat in a series of muscle twitches

1928 ◽  
Vol 103 (723) ◽  
pp. 171-182 ◽  
Keyword(s):  
Heat Production ◽  
Anaerobic Condition ◽  
Heat Rate ◽  
Present Series ◽  
Simple Scheme ◽  
Minimum Value ◽  
Beat Rate ◽  
Single Twitch ◽  
Physical Effects ◽  
Initial Heat

In 1922, Hartree and Hill (1) described a delayed heat-production after a short tetanic stimulus in a muscle deprived of oxygen, amounting to about one-third of the recovery beat in oxygen. In 1923 the same authors (2) re-examined the matter, with greater precautions to exclude oxygen, and found a "most probable " value for this delayed anaerobic heat of about one-quarter of the initial, or one-sixth of the recovery, heat. The existence of this heat has remained an obscure phenomenon, a complication in an otherwise comparatively simple scheme, and a further attempt was made by Furusawa and Hartree (3) in 1926 to trace its source. In spite of all precaution to exclude oxygen, and to obviate physical effects (lack of uniformity in the muscle, etc.) which might produce the same apparent result, the delayed heat persisted, and Furusawa and Hartree concluded that its minimum value was about 12 per cent, of the initial heat ; in many cases. It was more, sometimes much more. It should be noted that all the investigations referred to dealt with a short tetanus, not with a single twitch. The increment produced by stimulation in the resting heat-rate of a muscle under anaerobic condition, described in a previous paper of the present series, is one of the factors responsible for the effect discussed. Unless the galvanometer-zero, and the temperature of the thermopile-chamber, be extremely constant, it is easy to misinterpret the permanent shift of position of the galvanometer alter stimulation in nitrogen, and to deduce the existence of a long-continued slow production of beat gradually diminishing to zero. The reactions underlying the increment in the resting beat-rate are not part of the process of activity itself, although induced by it, and it is incorrect to attribute the energy the liberate to the preceding contraction; this is obviously the case, since the increment in beat-rate we know now to be permanent, so that the energy liberated is not constant but proportional to the time during which one choose to follow the galvanometer defection. It will be shown, indeed, by Hartree and Hill in a later paper of this series that such anaerobic delayed heat as really exists, in the case of a tetanus, occupies only a minute or two alter the stimulus; the long-continued part of the delayed heat, described in each of the three papers cited above, is an error due to a misinterpretation of the facts, which could not then be observed with the same accuracy as is possible now.

scholarly journals The Influence of Sodium-Free Solutions on the Membrane Potential of Frog Muscle Fibers

1963 ◽  
Vol 47 (1) ◽  
pp. 117-132 ◽  
Author(s):  
L. J. Mullins ◽  
K. Noda
Keyword(s):  
Membrane Potential ◽  
Activity Coefficients ◽  
Muscle Fibers ◽  
Frog Muscle ◽  
Sartorius Muscle ◽  
Coupling Ratio ◽  
Nernst Equation ◽  
Ringer’S Solution ◽  
Na Efflux ◽  
Frog Sartorius

The membrane potential of frog sartorius muscle fibers in a Cl- and Na-free Ringer's solution when sucrose replaces NaCl is about the same as that in normal Ringer's solution. The K+ efflux is also about the same in the two solutions but muscles lose K and PO4 in sucrose Ringer's solutions. The membrane potential in sucrose Ringer's solution is equal to that given by the Nernst equation for a K+ electrode, when corrections are made for the activity coefficients for K+ inside and outside the fiber. For a muscle in normal Ringer's solution, the measured membrane potential is within a few millivolts of EK. This finding is incompatible with a 1:1 coupled Na-K pump. It is consistent with either no coupling of Na efflux to K influx, or a coupling ratio of 3 or greater.

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 A new method for excitation-contraction uncoupling in frog skeletal muscle.

1978 ◽  
Vol 78 (3) ◽  
pp. 782-784 ◽  
Author(s):  
J del Castillo ◽  
G Escalona de Motta
Keyword(s):  
Electrical Activity ◽  
Prolonged Exposure ◽  
Neuromuscular Block ◽  
Ringer Solution ◽  
Mechanical Activity ◽  
Sartorius Muscle ◽  
Nerve Branch ◽  
Miniature Endplate Potentials ◽  
Endplate Potentials ◽  
Frog Sartorius

The mechanical activity of frog sartorius muscle fibers can be uncoupled from the electrical activity of their surface membranes by immersing the preparation in Ringer solution containing either 1.5 or 2.0 M of formamide for 15--20 min. This uncoupling is not reversed when the muscle is transferred to normal frog Ringer solution. Formamide does not affect the electrical activity of the sciatic nerve branch, and both endplate potentials and miniature endplate potentials may be recorded from the uncoupled muscles. Prolonged exposure to formamide, beyond the time needed to paralyze, causes neuromuscular block.

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