التفاصيل البيبلوغرافية
| العنوان: |
Properties of Calcium Transients in Rabbit Atrial Myocytes |
| المؤلفون: |
Mark B. Cannell, Cherrie H.T. Kong, Hanne C. Gadeberg, Andrew F. James |
| المصدر: |
Biophysical Journal. 104(2):434a-435a |
| بيانات النشر: |
Elsevier BV, 2013. |
| سنة النشر: |
2013 |
| مصطلحات موضوعية: |
SERCA, Confocal, Endoplasmic reticulum, Sarcoplasm, Analytical chemistry, Biophysics, Washout, chemistry.chemical_element, Calcium, chemistry.chemical_compound, Cytosol, chemistry, lipids (amino acids, peptides, and proteins), sense organs, Caffeine, skin and connective tissue diseases |
| الوصف: |
In comparison to ventricular myocytes, there is relatively little information regarding the transport mechanisms underlying the Ca2+ transient in atrial cells. In this study, we focus on the contribution of the sarcoplasmic Ca-ATPase (SERCA) and Na/Ca exchanger (NCX) to the removal of Ca2+ from the cytosol in atrial myocytes. Isolated rabbit atrial myocytes were loaded with fluo-4-AM and superfused with a Tyrode's solution at room temperature (20 – 24 °C) in a chamber on a Zeiss Pascal LSM5 confocal microscope. Cells were electrically stimulated at 1 Hz via bath electrodes and linescan images obtained by scanning transversely across the cell. Electrically stimulated Ca2+ transients were initiated at the periphery of the cell, rising to a peak within 66.5 ± 15.4 ms. The peak of the transient at the center of the cell was delayed and had reduced amplitude compared with the transient at the cell edge. The decay phase of the twitch transient averaged across the cell width was fitted by a single exponential (ktwitch = 1.71 ± 0.26 s−1). Rapid application of 10 mM caffeine to unload the sarcoplasmic reticulum (SR) produced a large transient that decayed with a rate constant (kcaff) of 0.19 ± 0.01 s−1. Following the washout of caffeine, twitch Ca2+ transients were markedly diminished but recovered to a steady-state within ∼20 s. Subsequent rapid application of caffeine in the presence of Ni2+ (10 mM) produced a large Ca2+ transient that recovered with a rate constant, kNi, of 0.02 ± 0.004 s−1. SERCA, NCX and slow pathways were calculated to contribute, respectively, 87.4 ± 1.8%, 10.8 ± 1.4% and 1.8± 0.5% of the total Ca2+ flux. In conclusion, the overall calcium extrusion pattern appears similar to ventricular myocytes. |
| تدمد: |
0006-3495 |
| DOI: |
10.1016/j.bpj.2012.11.2417 |
| URL الوصول: |
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5d6e0dbb71059a6bfd055da007f03d1f |
| Rights: |
OPEN |
| رقم الانضمام: |
edsair.doi.dedup.....5d6e0dbb71059a6bfd055da007f03d1f |
| قاعدة البيانات: |
OpenAIRE |