Phosphocreatine


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Related to Phosphocreatine: creatine kinase

phosphocreatine

[¦fäs·fō′krē·ə‚tēn]
(biochemistry)
C4H10N3O5P Creatine phosphate, a phosphoric acid derivative of creatine which contains an energy-rich phosphate bond; it is present in muscle and other tissues, and during the anaerobic phase of muscular contraction it hydrolyzes to creatine and phosphate and makes energy available. Abbreviated PC.

Phosphocreatine

 

(creatine phosphate, creatine phosphoric acid), a product of creatine phosphorylation; an energy-rich compound.

Phosphocreatine was first discovered in 1927 in fresh specimens of muscle tissue. It can be prepared by treating creatine with POCI3 in an alkaline medium. One of the energy sources for muscle contraction is the readily reversible decomposition of phosphocreatine, catalyzed by the enzyme creatinase: phosphocreatine + ADP ⇄ creatine + ATP. A decrease in the ATP content in the tissues leads to the decomposition of phosphocreatine; an increase in ATP content leads to its synthesis. Thus, phosphocreatine forms a reserve of energy-rich phosphate, both the phosphate and stored energy of which can be used in the formation of ATP. In tissues, phosphocreatine undergoes gradual spontaneous decomposition to yield inorganic phosphate and creatinine, which is eliminated with the urine. Arginine phosphate replaces phosphocreatine in many invertebrates (for example, insects).

N. P. MESHKOVA

References in periodicals archive ?
Skeletal muscle phosphocreatine recovery in exercise-trained humans is dependent on O2 availability.
Inhibition of muscle phosphocreatine resynthesis by caffeine after creatine loading.
Although a detailed examination of the muscular system of the mutant mice revealed the inability to perform the burst activity; phosphocreatine and ATP concentrations appeared normal in CK-M-deficient skeletal muscles.
These spectra showed the relative amounts of inorganic phosphorus and the metabolites phosphocreatine and adenosine triphosphate -- normally present in minute quantities and very difficult to detect.
Increased oxygen availability improves intermittent sprint performance by increasing aerobic contribution for the re-synthesis of adenosine triphosphate during sprint and accelerating the re-synthesis of phosphocreatine after sprint (Glaister, 2005).
A deep fall in contractile function allows them to conserve limited stores of ATP and phosphocreatine. This is realized by means of limiting [Ca.sup.2+] entry into cells [1] due to the shortening of action potential and early release of [K.sup.+], which gradually reduces excitability of cardiomyocytes.
The different work-to-rest ratio in the two exercises influenced the metabolism, because it has been shown that a shorter rest time between repeated sprints might result in smaller restoration of phosphocreatine stores (2).
Creatine kinase catalyzes the conversion of creatine and consumes adenosine triphosphate (ATP) to create phosphocreatine and adenosine diphosphate, therefore ATP can be generated from phosphocreatine and ADP.
The extent to which an individual can maintain their sprint performance is known as "repeated sprint ability" (RSA) [6] which is largely dependent on the extent of Phosphocreatine (PCr) resynthesis [7] and the removal of hydrogen ions ([H.sup.+]) from the muscle during recovery between bouts.
"Pyruvate Utilization, Phosphocholine and Adenosine Triphosphate (ATP) Are Markers of Human Breast Tumor Progression." (3) This study compared breast cancer cells with normal breast cells and found a 30% decrease in ATP levels and an 83% decrease in phosphocreatine levels "suggests impaired mitochondria' metabolism in the breast carcinoma cell lines." "These results demonstrate that diminished mitochondrial energy generation may be quantitatively related to the progression state of human breast cancer cells." That is, malignancy potentially correlates with mitochondrial dysfunction.
rosea did not improve blood oxygenation after induced hypoxia and skeletal muscle phosphocreatine (PCr) recovery after exhaustive exercise respectively.
For assessment of AC activity, aliquots of the same membrane preparation were incubated for 30 min at 30[degrees]C with final concentrations of 100 mM Tris-HCl (pH 7.4), 10 mM theophylline, 1 mM ATP, 2 mM Mg[Cl.sub.2], 1 mg/mL bovine serum albumin, and a creatine phosphokinase-ATP-regenerating system consisting of 10 mM sodium phosphocreatine and 8 IU/mL phosphocreatine kinase, with 10 [micro]M GTP in a total volume of 250 [micro]L.