scholarly journals Lactic acid in mammalian cardiac muscle.— Part III. changes in hydrogen-ion concentration. (Preliminary note.)

1925 ◽  
Vol 99 (694) ◽  
pp. 26-27 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Lactic Acid ◽  
Glass Electrode ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Accurate Estimation ◽  
Rigor Mortis ◽  
Preliminary Note ◽  
Hydrogen Ion Concentration ◽  
Electrode Method

Experiments have been made to determine (1) the hydrogen-ion concentra­tions of cardiac and skeletal muscle minced in the cold ( a ) under normal con­ditions, ( b )after stimulation to fatigue, and ( c ) in rigor mortis, and (2) the change of hydrogen-ion concentration following the addition of known amounts of lactic acid. The measurements were made by means of the glass electrode method (Kerridge (1)). The results given are quantitatively only preliminary in character, pending (i) the repetition of the experiments on a larger number of animals, and (ii) the more accurate estimation of corrections due to dilution with saline, &c.

scholarly journals The heat of rigor of mammalian muscle

1930 ◽  
Vol 107 (750) ◽  
pp. 214-222 ◽  
Keyword(s):  
Lactic Acid ◽  
Heat Production ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Post Mortem ◽  
Rigor Mortis ◽  
Hydrogen Ion Concentration ◽  
Mammalian Muscle ◽  
Quantity Of Heat

The stiffening of muscle in rigor mortis is closely related to gelation of the muscle plasma (Smith, 1930). Neither the stiffening of the muscle (Hoet and Marks, 1926) nor the gelation of the plasma is immediately due to an increase in the hydrogen-ion concentration of the muscle, but, apart from the formation of lactic acid, no reaction is known to occur post-mortem which might be held responsible for the coagulation of the plasma. It was with a view to the detection of any such reaction that the following measurements of the heat production accompanying rigor mortis were made. The heat of rigor mortis has not previously been measured, although A. V. Hill (1912) measured the heat produced by frog’s muscles undergoing heat and chloroform rigor. The result suggested that the conversion of glycogen into lactic acid accounted for almost the whole of the heat produced. This has been found to be the case in the muscle of a normal well-fed rabbit when passing into rigor mortis , and also in the case of fatigued or exhausted muscle, but starved animals produce a larger quantity of heat than can be accounted for by the lactic acid produced.

scholarly journals PHYSICAL PROPERTIES OF THE ALLANTOIC AND AMNIOTIC FLUIDS OF THE CHICK

1943 ◽  
Vol 26 (6) ◽  
pp. 503-512 ◽  
Author(s):  
Paul Andrew Walker
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Glass Electrode ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Two Fluids ◽  
Electrode Technique

1. The hydrogen ion concentration of the allantoic and amniotic fluids of the developing chick has been determined over the period of incubation between the 7th and 19th days using the glass electrode technique. 2. Changes in this property have been related to changes in the chemical composition of these two fluids. 3. The results of this investigation have been compared with those obtained by other workers. Excellent confirmation has been afforded the work of Yamada, whereas the work of Aggazzotti, which has long been accepted, is shown to be in error.

scholarly journals The Influence of Hydrogen Ion Concentration on Calcium Binding and Release by Skeletal Muscle Sarcoplasmic Reticulum

1972 ◽  
Vol 59 (1) ◽  
pp. 22-32 ◽  
Author(s):  
Yoshiaki Nakamaru ◽  
Arnold Schwartz
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Calcium Binding ◽  
Calcium Release ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Ph Change ◽  
Release Process ◽  
Hydrogen Ion Concentration ◽  
Calcium Loading

Calcium release and binding produced by alterations in pH were investigated in isolated sarcoplasmic reticulum (SR) from skeletal muscle. When the pH was abruptly increased from 6.46 to 7.82, after calcium loading for 30 sec, 80–90 nanomoles (nmole) of calcium/mg protein were released. When the pH was abruptly decreased from 7.56 to 6.46, after calcium loading for 30 sec, 25–30 nmole of calcium/mg protein were rebound. The calcium release process was shown to be a function of pH change: 57 nmole of calcium were released per 1 pH unit change per mg protein. The amount of adenosine triphosphate (ATP) bound to the SR was not altered by the pH changes. The release phenomenon was not due to alteration of ATP concentration by the increased pH. Native actomyosin was combined with SR in order to study the effectiveness of calcium release from the SR by pH change in inducing super-precipitation of actomyosin. It was found that SR, in an amount high enough to inhibit superprecipitation at pH 6.5, did not prevent the process when the pH was suddenly increased to 7.3, indicating that the affinity of SR for calcium depends specifically on pH. These data suggest the possible participation of hydrogen ion concentration in excitation-contraction coupling.

scholarly journals THE COLLOIDAL BEHAVIOR OF PROTEINS

1921 ◽  
Vol 3 (4) ◽  
pp. 557-564 ◽  
Author(s):  
Jacques Loeb
Keyword(s):  
Aqueous Solution ◽  
Osmotic Pressure ◽  
Chloride Solution ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Preliminary Note ◽  
Hydrogen Ion Concentration ◽  
Chloride Solutions ◽  
The Difference ◽  
Two Sides

1. It is well known that neutral salts depress the osmotic pressure, swelling, and viscosity of protein-acid salts. Measurements of the P.D. between gelatin chloride solutions contained in a collodion bag and an outside aqueous solution show that the salt depresses the P.D. in the same proportion as it depresses the osmotic pressure of the gelatin chloride solution. 2. Measurements of the hydrogen ion concentration inside the gelatin chloride solution and in the outside aqueous solution show that the difference in pH of the two solutions allows us to calculate the P.D. quantitatively on the basis of the Nernst formula See PDF for Equation if we assume that the P.D. is due to a difference in the hydrogen ion concentration on the two sides of the membrane. 3. This difference in pH inside minus pH outside solution seems to be the consequence of the Donnan membrane equilibrium, which only supposes that one of the ions in solution cannot diffuse through the membrane. It is immaterial for this equilibrium whether the non-diffusible ion is a crystalloid or a colloid. 4. When acid is added to isoelectric gelatin the osmotic pressure rises at first with increasing hydrogen ion concentration, reaches a maximum at pH 3.5, and then falls again with further fall of the pH. It is shown that the P.D. of the gelatin chloride solution shows the same variation with the pH (except that it reaches its maximum at pH of about 3.9) and that the P.D. can be calculated from the difference of pH inside minus pH outside on the basis of Nernst's formula. 5. It was found in preceding papers that the osmotic pressure of gelatin sulfate solutions is only about one-half of that of gelatin chloride or gelatin phosphate solutions of the same pH and the same concentration of originally isoelectric gelatin; and that the osmotic pressure of gelatin oxalate solutions is almost but not quite the same as that of the gelatin chloride solutions of the same pH and concentration of originally isoelectric gelatin. It was found that the curves for the values for P.D. of these four gelatin salts are parallel to the curves of their osmotic pressure and that the values for pH inside minus pH outside multiplied by 58 give approximately the millivolts of these P.D. In this preliminary note only the influence of the concentration of the hydrogen ions on the P.D. has been taken into consideration. In the fuller paper, which is to follow, the possible influence of the concentration of the anions on this quantity will have to be discussed.

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