## Neubauer et al. (1) report on the spin-lattice relaxation times (T,) of high-energy phosphates in the human myocardium at 1.5 T. Their values of 6.1 ? 0.5 (SD) s for PCr and 5.4 t 0.5 s to 5.8 +-1 s for the ATP phosphates differ
Determination of myocardial high-energy phosphates using bioluminescence
β Scribed by Robert J. Ellis; Christopher Gardner
- Publisher
- Elsevier Science
- Year
- 1980
- Tongue
- English
- Weight
- 521 KB
- Volume
- 105
- Category
- Article
- ISSN
- 0003-2697
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β¦ Synopsis
The measurement of myocardial high-energy phosphates (HEP) has become essential in the evaluation of current methods of myocardial protection both in the experimental and clinical setting. Assays for high-energy phosphates have required as much as 50 mg of myocardial tissue which prevents repeated biopsies in the clinical setting as well as in the experimental laboratory. Using the reaction of bioluminescence described by McElroy W. D. and B. L. Strehler (1949, Arch. Biol. Chem. 22, 420), we have developed a technique to measure both adenosine triphosphate and creatine phosphate on samples of myocardial tissue weighing less than 10 mg. A liquid scintillation counter measures the light produced by ATP when added to a firefly extract containing luciferin/luciferase. The reaction is complete in seconds and is detected in the counter during the first 10-s count. Repeated samples have demonstrated a variation of less than 4% between samples. A 25~~1 sample is diluted up to 40 ~1 of firefly extract for detection of adenosine triphosphate. Creatine phosphate is measured by the in vitro production of adenosine triphosphate which is maximum in 10 min when adenosine diphosphate and creatine kinase are added. Again reproducibility of repeated analyses demonstrates a 4% difference in creatine phosphate values. The rapidity, reproducibility, and ability to use ultramicrosamples allows investigators to analyze high-energy phosphates during various methods of myocardial protection currently used in clinical setting.
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## Abstract Whether changes of cardiac highβenergy phosphate concen trations occur over the cardiac cycle remains controversial. The hypothesis was that such cyclical changes are accentu ated during acute or chronic myocardial stress. Isolated rat hearts were perfused under four conditions: (1) con