Der Austausch von radioaktivem,32P-markiertem Orthophosphat mit dem P?, P? und P? von ATP und mit Kreatinphosphat bei Muskelruhe, Temperaturvariation und elektrischer Reizung

Fleckenstein, A.; Janke, J.; Schwoerer, W.; Gabelmann, L.

doi:10.1007/bf00595650

Cited by 35 publications

(6 citation statements)

References 24 publications

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“…If diffusion of PCr in vertebrate muscles is also the rate limiting step, our results are in contradiction with previous results in which the transference of phosphate from PCr to ADP was measured and in which the incorporation of the 32P into the intracellular high-energy phosphate compounds was attempted from the extracellular space, across the sarcolemma [Sacks, 1940;Sacks and Cleland, 1960;Fleckenstein and Janke, 1957;Fleckenstein, Gerlach Janke and Marmier, 1960]. If the rate of Lohman's ieaction in vertebrates is as large as in the case of the equivalent reaction in crustacea, then those previous experiments were carried out when the specific activities had reached equilibrium and, therefore, the phosphate exchange via the Lohman's reaction could not be detected.…”

Section: Discussioncontrasting

confidence: 99%

Phosphate Exchange Between High‐Energy Phosphate Compounds in Resting Crustacean Muscle

Alvarez¹,

Luxoro²,

Nassar-Gentina³

et al. 1980

Exp Physiol

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Single giant muscle fibres from Megabalanuiiis psittactis were microinjected with ATP-32P or internally perfused with a solution containing 32P-PArg in an attempt to demonstrate, in the absence of inhibitors, ATP utilization during mechanical activity with negative results. The rate constant of transfer of 32p from microinjected 32P-PArg to endogenous ATP was studied at two different temperatures, obtaining a Q1o of 108+0 12. It is concluded that the rate limiting step in the process of transference of phosphate in the resting muscle from balanus is the intracellular diffusion of PArg and not the rate at which the equivalent of Lohman's reaction in invertebrates proceeds.It is generally accepted that adenosine triphosphate (ATP) and phosphocreatine (PCr) are split during one of the steps of the contraction-recovery cycle in muscle from vertebrates [Wilkie, 1968a, b;Mommaerts, 1969;Mommaerts and Wallner, 1967;Woledge, 1971]. It is also thought that the ADP generated is rephosphorylated from PCr by the Lohman reaction so that no net change in concentration of ATP can be detected except when the Lohman reaction is blocked by 1-fluoro-2, 4-dinitrobenzene (FDNB;) [Cain and Davies, 1962]. In general ATP and PCr splitting reactions are thought to take place during the initial part of the mechanical events. In the measurement of the changes in ATP and PCr level in muscle one encounters some difficulties; chief among them are (1) arresting the chemical changes in the muscle by sufficiently rapid freezing and (2) making an extract of the frozen muscle containing all the substances of interest and analysing it without producing further chemical changes. Furthermore, the results are obtained by comparison of the substitute level in two muscles which, as a rule, are initially different. Although the method presented in the preceding paper resolves this last difficulty [Nassar-Gentina and Rojas, 1980], the rates of phosphate transfer under resting conditions have to be determined accurately before attempting to measure the effects of mechanical activation of the fibres.

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Section: Discussioncontrasting

confidence: 99%

Phosphate Exchange Between High‐Energy Phosphate Compounds in Resting Crustacean Muscle

Alvarez¹,

Luxoro²,

Nassar-Gentina³

et al. 1980

Exp Physiol

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“…It is equally conceivable, however, that, under the conditions of our experiments, XP enters into exchange during contracture and relaxation with two phosphate pools, one less labelled with 32p than the other. Fleckenstein & Janke (1957) have indeed shown that the overall labelling of PC is significantly less than that of the terminal phosphate residue of ATP in the rectus abdominis after incubation periods similar to our own. Although the scatter in the phosphate contents of the solid muscle residues makes it difficult to reach a clear decision in this regard, it is noteworthy that in no series of experiments does the mean phosphate content of the controls exceed that of the contracted muscles.…”

Section: Discussionsupporting

confidence: 88%

Exchange of structurally bound phosphate in muscular activity

Cheesman¹,

Hilton²

1966

The Journal of Physiology

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SUMMARY1. When rectus abdominis and sartorius muscles of the frog are incubated with 32P-orthophosphate and subsequently minced, extracted with carbonate-bicarbonate buffer and water, and converted to acetone powders, considerable radioactivity remains associated with the solid material.2. Muscles labelled with 32p and subjected to contracture at room temperature with KCI or ACh yield acetone powders which, in comparison with those of uncontracted control muscles, show a significantly decreased radioactivity. There is no evidence for a corresponding decrease in the total phosphate content.3. Relaxation of a contracted muscle restores the 32p content of its acetone powder at least to the level for a resting, control muscle.4. When two recti are incubated with 5 x 10-4 M-DNP after labelling with 32p, subsequent depolarization of one muscle with KCI usually results in an increase in the activity of the bound phosphate fraction, with little or no contracture in addition to that already caused by the DNP.5. It is concluded that the bound phosphate fraction undergoes exchange during activation, shortening and relaxation of muscle, and may represent a source of energy for muscular activity.

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“…This is in accordance with the work of Fleckenstein and Janke (1957), Harth and Mandel (1961) and Clauser et al (1962). This is in accordance with the work of Fleckenstein and Janke (1957), Harth and Mandel (1961) and Clauser et al (1962).…”

Section: Calculation Of Specific Radioactivitiessupporting

confidence: 93%

The Effect of Epinephrine and Dibutyryl 3‘,5’ Cyclic AMP on the Incorporation of ³²P Inorganic Phosphate into Adenine Nucleotides and Guanine Nucleotides of the Intact Isolated Rat Diaphragm

Walaas

1970

Acta Physiologica Scandinavica

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WALAAS, E. and 0. WALAAS. T h e effect of epinephrine and dibutyryl3',5' cyclic AMPon the incorporation of y2P inorganic phosphate into adenine nucleotides and guanine nucleptides of the isolated intact rat diaphragm. Acta physiol. scand. 78. 3 9 3 4 0 3 .The influence of epinephrine and dibutyryl 3',5' cyclic AMP on the incorporation of 32P inorganic phosphate into adenine nucleotides and guanine nucleotides in the rat diaphragm has been investigated. Intact rat diaphragms were incubated in Krebs Ringer bicarbonate medium containing 32P inorganic phosphate without added substrate. Epinephrine promoted a marked increase of the specific activity of ATP, GTP and GDP which could be demonstrated after 10 min incubation. The specific activity of ADP was less and only slightly increased by epinephrine. I n the presence of caffeine the stimulation of 32P labelling of ATP by epinephrine was slightly enhanced. Epinephrine also promoted an increase of the specific activity of intracellular inorganic phosphate while the content of inorganic phosphate in the diaphragm was slightly decreased. The stimulatory effect of epinephrine on the specific activity of mononucleotides was not inhibited by ouabain. I n a medium where sodium chloride isoosmotically had been replaced by choline chloride S2P labelling of ATP was greatly depressed. Under these conditions epinephrine also promoted increased specific activity of ATP. During incubation of the diaphragm in the presence of dibutyryl 3',5' cyclic AMP increased s2P labelling of ATP and ADP did occur. The effect was less pronounced than observed with epinephrine and no effect by dibutyryl 3',5' cyclic AMP on the specific activity of intracellular inorganic phosphate was observed. I t is indicated that the increased incorporation of 32P inorganic phosphate into mononucleotides promoted by epinephrine is due to activation of adenyl cyclase as well as to increased influx of s2P inorganic phosphate from the medium.

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Der Austausch von radioaktivem,32P-markiertem Orthophosphat mit dem P?, P? und P? von ATP und mit Kreatinphosphat bei Muskelruhe, Temperaturvariation und elektrischer Reizung

Cited by 35 publications

References 24 publications

Phosphate Exchange Between High‐Energy Phosphate Compounds in Resting Crustacean Muscle

Phosphate Exchange Between High‐Energy Phosphate Compounds in Resting Crustacean Muscle

Exchange of structurally bound phosphate in muscular activity

The Effect of Epinephrine and Dibutyryl 3‘,5’ Cyclic AMP on the Incorporation of ³²P Inorganic Phosphate into Adenine Nucleotides and Guanine Nucleotides of the Intact Isolated Rat Diaphragm

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Der Austausch von radioaktivem,32P-markiertem Orthophosphat mit dem P?, P? und P? von ATP und mit Kreatinphosphat bei Muskelruhe, Temperaturvariation und elektrischer Reizung

Cited by 35 publications

References 24 publications

Phosphate Exchange Between High‐Energy Phosphate Compounds in Resting Crustacean Muscle

Phosphate Exchange Between High‐Energy Phosphate Compounds in Resting Crustacean Muscle

Exchange of structurally bound phosphate in muscular activity

The Effect of Epinephrine and Dibutyryl 3‘,5’ Cyclic AMP on the Incorporation of 32P Inorganic Phosphate into Adenine Nucleotides and Guanine Nucleotides of the Intact Isolated Rat Diaphragm

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The Effect of Epinephrine and Dibutyryl 3‘,5’ Cyclic AMP on the Incorporation of ³²P Inorganic Phosphate into Adenine Nucleotides and Guanine Nucleotides of the Intact Isolated Rat Diaphragm