Pulsed nuclear magnetic resonance study of 39K in frog striated muscle
Samples of 1 M KCl solution and 10 samples of intact frog striated muscle were studied at 4–7 degrees C and/or at 21–22 degrees C. Field inhomogeneity was minimized by using small sample volumes and by using a superconducting magnet designed specifically to provide highly homogeneous fields. In the...
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Published in | Biophysical journal Vol. 16; no. 12; pp. 1385 - 1398 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.12.1976
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Subjects | |
Online Access | Get full text |
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Summary: | Samples of 1 M KCl solution and 10 samples of intact frog striated muscle were studied at 4–7 degrees C and/or at 21–22 degrees C. Field inhomogeneity was minimized by using small sample volumes and by using a superconducting magnet designed specifically to provide highly homogeneous fields. In the present experiments, magnetic field inhomogeneity was measured to contribute less than 15% to the free induction decay observed for intracellular 39K. The signal-to-noise ratio of the measurements was enhanced by means of extensive time-averaging. The rates of nuclear relaxation for 39K in aqueous solution were 22 +/- 3 (mean +/- 95% confidence limits) s-1 at 4–7 degrees C and 15 +/- 2 s-1 at 21–22 degrees C. For intracellular 39K, (1/T2) was measured to be 327 +/- 22 s-1 and 229 +/- 10 s-1 at the lower and higher temperatures, respectively. The corresponding values for (1/T1) in the same muscle samples were 198 +/- 31 s-1 and 79 +/- 15 s-1 at 4–7 degrees C and at 21–22 degrees C, respectively. These results for 39K are similar to those previously obtained for intracellular 23Na. Since less than 1% of the intracellular 23Na has been estimated to be immobilized, fractional immobilization of intracellular 39K is also likely to be insubstantial. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-3495 1542-0086 |
DOI: | 10.1016/S0006-3495(76)85782-7 |