Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10753350 | Biochemical and Biophysical Research Communications | 2015 | 6 Pages |
Abstract
In the present study, we investigated the effects of infra-red laser irradiation on sarcomere dynamics in living neonatal cardiomyocytes of the rat. A rapid increase in temperature to >â¼38 °C induced [Ca2+]i-independent high-frequency (â¼5-10 Hz) sarcomeric auto-oscillations (Hyperthermal Sarcomeric Oscillations; HSOs). In myocytes with the intact sarcoplasmic reticular functions, HSOs coexisted with [Ca2+]i-dependent spontaneous beating in the same sarcomeres, with markedly varying frequencies (â¼10 and â¼1 Hz for the former and latter, respectively). HSOs likewise occurred following blockade of the sarcoplasmic reticular functions, with the amplitude becoming larger and the frequency lower in a time-dependent manner. The present findings suggest that in the mammalian heart, sarcomeres spontaneously oscillate at higher frequencies than the sinus rhythm at temperatures slightly above the physiologically relevant levels.
Keywords
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Seine A. Shintani, Kotaro Oyama, Norio Fukuda, Shin'ichi Ishiwata,