Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes
Heating cardiomyocytes to 38–42°C induces hyperthermal sarcomeric oscillations (HSOs), which combine chaotic instability and homeostatic stability. These properties are likely important for achieving periodic and rapid ventricular expansion during the diastole phase of the heartbeat. Compared with s...
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| Format: | Article |
| Language: | English |
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The Biophysical Society of Japan
2024-01-01
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| Series: | Biophysics and Physicobiology |
| Subjects: | |
| Online Access: | https://doi.org/10.2142/biophysico.bppb-v21.0006 |
| _version_ | 1827338204758409216 |
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| author | Seine A. Shintani |
| author_facet | Seine A. Shintani |
| author_sort | Seine A. Shintani |
| collection | DOAJ |
| description | Heating cardiomyocytes to 38–42°C induces hyperthermal sarcomeric oscillations (HSOs), which combine chaotic instability and homeostatic stability. These properties are likely important for achieving periodic and rapid ventricular expansion during the diastole phase of the heartbeat. Compared with spontaneous oscillatory contractions in cardiomyocytes, which are sarcomeric oscillations induced in the presence of a constant calcium concentration, we found that calcium concentration fluctuations cause chaotic instability during HSOs. We believe that the experimental fact that sarcomeres, autonomously oscillating, exhibit such instability due to the action of calcium concentration changes is important for understanding the physiological function of sarcomeres. Therefore, we have named this chaotic sarcomere instability that appears under conditions involving changes in calcium concentration as Sarcomere Chaos with Changes in Calcium Concentration (S4C). Interestingly, sarcomere instability that could be considered S4C has also been observed in the relaxation dynamics of EC coupling. Unlike ADP-SPOCs and Cell-SPOCs under constant calcium concentration conditions, fluctuations in oscillation amplitude indistinguishable from HSOs were observed. Additionally, like HSO, a positive Lyapunov exponent was measured. S4C is likely a crucial sarcomeric property supporting the rapid and flexible ventricular diastole with each heartbeat of the heart. |
| first_indexed | 2024-03-07T19:11:21Z |
| format | Article |
| id | doaj.art-73eaf52d47f14591b9e7bc8395b19e60 |
| institution | Directory Open Access Journal |
| issn | 2189-4779 |
| language | English |
| last_indexed | 2024-03-07T19:11:21Z |
| publishDate | 2024-01-01 |
| publisher | The Biophysical Society of Japan |
| record_format | Article |
| series | Biophysics and Physicobiology |
| spelling | doaj.art-73eaf52d47f14591b9e7bc8395b19e602024-03-01T00:45:08ZengThe Biophysical Society of JapanBiophysics and Physicobiology2189-47792024-01-012110.2142/biophysico.bppb-v21.0006Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytesSeine A. Shintani0Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, JapanHeating cardiomyocytes to 38–42°C induces hyperthermal sarcomeric oscillations (HSOs), which combine chaotic instability and homeostatic stability. These properties are likely important for achieving periodic and rapid ventricular expansion during the diastole phase of the heartbeat. Compared with spontaneous oscillatory contractions in cardiomyocytes, which are sarcomeric oscillations induced in the presence of a constant calcium concentration, we found that calcium concentration fluctuations cause chaotic instability during HSOs. We believe that the experimental fact that sarcomeres, autonomously oscillating, exhibit such instability due to the action of calcium concentration changes is important for understanding the physiological function of sarcomeres. Therefore, we have named this chaotic sarcomere instability that appears under conditions involving changes in calcium concentration as Sarcomere Chaos with Changes in Calcium Concentration (S4C). Interestingly, sarcomere instability that could be considered S4C has also been observed in the relaxation dynamics of EC coupling. Unlike ADP-SPOCs and Cell-SPOCs under constant calcium concentration conditions, fluctuations in oscillation amplitude indistinguishable from HSOs were observed. Additionally, like HSO, a positive Lyapunov exponent was measured. S4C is likely a crucial sarcomeric property supporting the rapid and flexible ventricular diastole with each heartbeat of the heart.https://doi.org/10.2142/biophysico.bppb-v21.0006sarcomere chaoshyperthermal sarcomeric oscillationscontraction rhythm homeostasisexcitation–contraction coupling |
| spellingShingle | Seine A. Shintani Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes Biophysics and Physicobiology sarcomere chaos hyperthermal sarcomeric oscillations contraction rhythm homeostasis excitation–contraction coupling |
| title | Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes |
| title_full | Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes |
| title_fullStr | Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes |
| title_full_unstemmed | Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes |
| title_short | Observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes |
| title_sort | observation of sarcomere chaos induced by changes in calcium concentration in cardiomyocytes |
| topic | sarcomere chaos hyperthermal sarcomeric oscillations contraction rhythm homeostasis excitation–contraction coupling |
| url | https://doi.org/10.2142/biophysico.bppb-v21.0006 |
| work_keys_str_mv | AT seineashintani observationofsarcomerechaosinducedbychangesincalciumconcentrationincardiomyocytes |