Abstract
Direct measurements of free Ca2+ in heart cells are needed for an understanding of the regulation of contractility. We developed and used Ca2+-sensitive microelectrodes with fine tips, stable properties and ample sensitivity to free Ca2+ in the sub-micromolar range. In quiescent ventricular muscle, measurements which passed tests for electrode sealing and cell viability gave a mean free Ca2+ concentration of 0.26 μM. During contractures, we recorded Ca2+ transients rising as high as 10 μM. In studying the effects of catecholamines on free Ca2+ and force, we found evidence that adrenaline can reduce myofibrillar Ca2+ sensitivity in intact heart muscle.
Original language | English (US) |
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Pages (from-to) | 845-850 |
Number of pages | 6 |
Journal | Nature |
Volume | 286 |
Issue number | 5776 |
DOIs | |
State | Published - 1980 |
Externally published | Yes |
ASJC Scopus subject areas
- General