Quantification of calcium release from the sarcoplasmic reticulum in rainbow trout atrial myocytes

1999 ◽  
Vol 438 (4) ◽  
pp. 545-552 ◽  
Author(s):  
L. Hove-Madsen ◽  
A. Llach ◽  
L. Tort
Keyword(s):  
Rainbow Trout ◽  
Sarcoplasmic Reticulum ◽  
Calcium Release ◽  
Atrial Myocytes

scholarly journals Atrial Fibrillation Is Associated With Increased Spontaneous Calcium Release From the Sarcoplasmic Reticulum in Human Atrial Myocytes

Circulation ◽  
2004 ◽  
Vol 110 (11) ◽  
pp. 1358-1363 ◽  
Author(s):  
Leif Hove-Madsen ◽  
Anna Llach ◽  
Antoni Bayes-Genís ◽  
Santiago Roura ◽  
Enrique Rodriguez Font ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sarcoplasmic Reticulum ◽  
Calcium Release ◽  
Atrial Myocytes ◽  
Human Atrial Myocytes

Na+/Ca2+-exchange activity regulates contraction and SR Ca2+ content in rainbow trout atrial myocytes

2000 ◽  
Vol 279 (5) ◽  
pp. R1856-R1864 ◽  
Author(s):  
Leif Hove-Madsen ◽  
Anna Llach ◽  
Lluis Tort
Keyword(s):  
Rainbow Trout ◽  
Sarcoplasmic Reticulum ◽  
Atrial Myocytes ◽  
Initial Value ◽  
Inhibitory Peptide ◽  
Patch Clamp Technique ◽  
Cell Shortening ◽  
Control Value ◽  
Patch Pipette ◽  
Exchange Activity

We have used the whole cell configuration of the patch-clamp technique to measure sarcolemmal Ca2+ transport by the Na+/Ca2+ exchanger (NCX) and its contribution to the activation and relaxation of contraction in trout atrial myocytes. In contrast to mammals, cell shortening continued, increasing at membrane potentials above 0 mV in trout atrial myocytes. Furthermore, 5 μM nifedipine abolished L-type Ca2+current ( I Ca) but only reduced cell shortening and the Ca2+ carried by the tail current to 66 ± 5 and 67 ± 6% of the control value. Lowering of the pipette Na+ concentration from 16 to 10 or 0 mM reduced Ca2+ extrusion from the cell from 2.5 ± 0.2 to 1.0 ± 0.2 and 0.5 ± 0.06 amol/pF. With 20 μM exchanger inhibitory peptide (XIP) in the patch pipette Ca2+extrusion 20 min after patch break was 39 ± 8% of its initial value. With 16, 10, and 0 mM Na+ in the pipette, the sarcoplasmic reticulum (SR) Ca2+ content was 47 ± 4, 29 ± 6, and 10 ± 3 amol/pF, respectively. Removal of Na+ from or inclusion of 20 μM XIP in the pipette gradually eliminated the SR Ca2+ content. Whereas I Ca was the same at −10 or +10 mV, Ca2+ extrusion from the cell and the SR Ca2+content at −10 mV were 65 ± 7 and 80 ± 4% of that at +10 mV. The relative amount of Ca2+ extruded by the NCX (about 55%) and taken up by the SR (about 45%) was, however, similar with depolarizations to −10 and +10 mV. We conclude that modulation of the NCX activity critically determines Ca2+ entry and cell shortening in trout atrial myocytes. This is due to both an alteration of the transsarcolemmal Ca2+ transport and a modulation of the SR Ca2+ content.

Intracellular citrate induces regenerative calcium release from sarcoplasmic reticulum in guinea-pig atrial myocytes

1995 ◽  
Vol 429 (6) ◽  
pp. 797-804 ◽  
Author(s):  
G. Callewaert ◽  
K. R. Sipido ◽  
E. Carmeliet ◽  
L. Pott ◽  
P. Lipp
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Guinea Pig ◽  
Calcium Release ◽  
Atrial Myocytes
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