Journal
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
Volume 278, Issue 2, Pages H444-H451Publisher
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpheart.2000.278.2.H444
Keywords
confocal laser scanning microscopy; fluo 3; coupling clamp
Funding
- NHLBI NIH HHS [HL-22562] Funding Source: Medline
Ask authors/readers for more resources
The L-type calcium current (I-Ca) is important in sustaining propagation during discontinuous conduction. In addition, I-Ca is altered during discontinuous conduction, which may result in changes in the intracellular calcium transient. To study this, we have combined the ability to monitor intracellular calcium concentration ([Ca2+](i)) in an isolated cardiac cell using confocal scanning laser fluorescence microscopy with our coupling clamp technique, which allows action potential propagation from the real cell to a real-time simulation of a model cell. Coupling a real cell to a model cell with a value of coupling conductance (G(C) = 8 nS) just above the critical value for action potential propagation results in both an increased amplitude and an increased rate of rise of the calcium transient. Similar but smaller changes in the calcium transient are caused by increasing G(C) to 20 nS. The increase of [Ca2+](i) by discontinuous conduction is less than the increase of I-Ca, which may indicate that much of [Ca2+](i) is the result of calcium released from the sarcoplasmic reticulum rather than the integration of I-Ca.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available