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. 1974 Apr;238(2):437–446. doi: 10.1113/jphysiol.1974.sp010535

Energetics of relaxation in frog muscle

Nancy A Curtin, Roger C Woledge
PMCID: PMC1330891  PMID: 4546216

Abstract

1. Changes in the levels of phosphocreatine (PCr) and ATP during relaxation after tetanic contraction have been observed and compared with the heat + work production during the same period.

2. The results were the same using 2 sec or 15 sec tetani and using 15 or 30 Hz stimulation.

3. During relaxation the mean chemical change (of ATP + PCr) was -0·105 ± 0·078 μmol/g muscle (n = 53). This change is less than would be required to explain the heat + work produced.

4. The PCr split during both 2 sec and 15 sec tetani (up to the last stimulus) was less than would be required to explain the heat + work produced. This confirms previous experiments.

5. It is concluded that the discrepancy between chemical change and heat + work production does not diminish during relaxation but actually increases.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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