Further observations on phosphagen

Eggleton, Philip; Eggleton, Grace Palmer

doi:10.1113/jphysiol.1928.sp002457

Cited by 61 publications

(17 citation statements)

References 8 publications

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“…That the same conception may be extended to other muscles seems probable from the numerous other cases where arginine or creatine phosphate has been shown to break down on stimulation or rigor ( , Holothuria, Pecten (Meyerhof, 1928); Raia clavata (Eggleton and Eggleton, 1928); N e r e i s, Slrongylocentrotus, Balanoglossus (the present work); frog heart (Eggleton, Eggleton and Clark, 1930). But the correlation between the type of contraction and (a) the type of phosphagen present, (6) the amount of phosphagen present, (c) the rate of its breakdown, is at present obscure.…”

Section: Discussionmentioning

confidence: 84%

A comparative study of the phosphagens, with some remarks on the origin of vertebrates

Needham

Needham²,

Baldwin

et al. 1932

Proc. R. Soc. Lond. B.

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The original discovery of labile phosphorus in muscular tissue by Eggleton and Eggleton (1927, a , b ) was rapidly followed by a succession of researches which demonstrated its great importance in muscular contraction. Fiske and Subbarow (1929) showed shortly afterwards that the phosphagen of the Eggletons was a compound containing equimolecular amounts of creatine and phosphoric acid, which, owing to its great instability in acid solution, had always previously been estimated as inorganic orthophosphate. It remained for the Eggletons (1928), Nachmansohn (1928, 1929, a , b ) and Meyerhof (1930) to delineate the functional importance of phosphagen in the muscle machinery, its breakdown under anaerobic conditions, its restitution in oxygen, and its energetical relations with the lactic acid cycle. In the course of their investigations, Eggleton and Eggleton (1928) examined the tissues of a certain number of invertebrates, and failed to find there any creatine phosphate. About the same time, however, Meyerhof and Lohmann (1928) reported the discovery of another phosphagen in crustacean muscle, a phosphagen in which the creatine portion of the molecule was replaced by arginine. This led to an examination of certain other invertebrates by Meyer hof himself (1928), from which a wide distribution of arginine phosphate in the invertebrate Phyla was suggested. Throughout the subsequent discussions it has been assumed that creatine phosphate may be regarded as characteristic of the Vertebrates and arginine phosphate as characteristic of the Invertebrates, although in the absence of thorough-going comparative researches, this view could only remain a very tentative generalisation. “The development of creatine phosphoric acid in the Vertebrates from the arginine phosphoric acid of the Invertebrates,” said Meyerhof (1930, p. 93) “must be regarded as a characteristic chemical mutation.” It is probable that Meyerhof was led to this sharp division by the general conclusions at which Hunter arrives in his monograph on creatine and creatinine (1928). Reviewing the various attempts which have been made to demonstrate the presence of creatine or creatinine in invertebrates ( e . g ., Wilson (1914), Myers (1920)) he points out that nearly all depend on the very unspecific Jaffe reaction, and concludes that up to the present time no good evidence exists in favour of their presence. But this is clearly only a negative conclusion, and the issue is therefore prejudged when Meyerhof writes, “Corresponding to the restriction of creatine to the vertebrate group, Eggleton and Eggleton failed to find phosphagen in the muscles of invertebrates” (1930, p. 92). Moreover, it is not possible to include all the data in the literature in Hunter’s condemnation, for Quast (1924) in reporting the presence of creatinine in the kidney of the gastropod, Cyclostoma elegans , states that he relied upon the tests of Weyl and Maschke as well as on that of Jaffe. And in any case, there remain large and important groups of animals (the Echinoids for instance) which have never been thoroughly examined either for creatine or for phosphagen.

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Section: Discussionmentioning

confidence: 84%

A comparative study of the phosphagens, with some remarks on the origin of vertebrates

Needham

Needham²,

Baldwin

et al. 1932

Proc. R. Soc. Lond. B.

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“…The rest of the phosphates inside the muscle fibre are in a combined form, incapable of diffusing. Phosphagen (Eggleton and Eggleton (8) ) and hexose phosphates make up a large part of this combined phosphorus, but probably not all. Presumably the free inorganic phosphate content of the living muscle is adjusted to an optimum level, and if the concentration inside the fibre be allowed to fall by the use of a solution containing little or no phosphate, the condition of the surviving muscle depreciates more rapidly than under more normal conditions.…”

Section: J* = Omentioning

confidence: 99%

Myothermic apparatus

1928

Proc. R. Soc. Lond. B.

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Myothermic Apparatus. % 117 Conclusion.The evidence at hand is still somewhat scanty and diffuse, and from the nature of the case it is difficult to accumulate detailed analyses of the combined fatty acids in various seed fats at anything but a very slow rate. Neverthe less, the facts set out above render it evident that, in the four orders discussed, there is a marked tendency towards the production of quite specific fatty acids. Other acids, of course, are also present, oleic and linoleic acids usually in fair to considerable proportions, and also minor amounts of such acids as palmitic, arachidic or lignoceric; but the four acids, lauric, myristic, erucic and petroselinic, stand out quite definitely in their nature and proportion in the respective cases of the four orders, Palmce, Myristicece, Cruoiferce and It is to be inferred that the seed fats of any given botanical order have certain characteristics of their own, and much in common with each other, differing from those of dissimilar orders.

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“…This rate must be submaximal at least in the cases of the two less demanding patterns of stimulation. It is interesting that as early as 1928 Eggleton & Eggleton (1928) and contracting muscle; this was revolutionary at the time, since it was generally believed that lactic acid itself was the direct cause of contraction. From the viewpoint of animal design it is surprising that glycolysis is not turned on more fully by the milder patterns of stimulation, for this would seem to provide a better stratagem for conserving PCr to use in emergencies.…”

Section: Physiologieal Methodsmentioning

confidence: 99%

Mechanical relaxation rate and metabolism studied in fatiguing muscle by phosphorus nuclear magnetic resonance.

Dawson¹,

Gadian²,

Wilkie³

1980

The Journal of Physiology

312

160

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SUMMARY1. We have used phosphorus nuclear magnetic resonance (31P NMR) to study muscular fatigue in anaerobic amphibian muscle. In this paper the biochemical and energetic changes that result from a series of tetani are related to the decrease in rate constant (1/r) for the final, exponential, phase of relaxation.2. Using 31P NMR we have measured the concentrations of phosphocreatine (PCr), inorganic phosphate (Pi) and ATP as well as the internal pH. From our measurements we have calculated [creatine], [free ADP], the free-energy change (more precisely, the affinity A = -dG/dg) for ATP hydrolysis and the rates of lactic acid production and of ATP hydrolysis. 3. We have found that 1/, the rate constant of relaxation, is correlated with each of the following, independently of the pattern of stimulation: isometric force production, all of the measured or calculated metabolite levels, pH and dG/dg.4. There is a clear dependence upon the pattern of stimulation of the relation between 1/r and each of the following: total duration of the experiment, number of contractions, rate of lactic acid production and rate of ATP hydrolysis.5. The rate of relaxation is linearly related to [PCr], [creatine], [Pi] and dG/d6. It is nonlinearly related to isometric force, [ATP], [H+] and rate of ATP hydrolysis.6. We conclude that the change in 1/IT, like that of isometric force, depends upon metabolic factors, and not upon any independent changes in the activation or deactivation of contraction. We suggest that 1/ir may depend upon the free-energy change for ATP hydrolysis which in turn may be related to the rate of Ca2+ uptake into the sarcoplasmic reticulum.

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Further observations on phosphagen

Cited by 61 publications

References 8 publications

A comparative study of the phosphagens, with some remarks on the origin of vertebrates

A comparative study of the phosphagens, with some remarks on the origin of vertebrates

Myothermic apparatus

Mechanical relaxation rate and metabolism studied in fatiguing muscle by phosphorus nuclear magnetic resonance.

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