Abstract
The relative contributions of the different Ca transport systems involved in cardiac relaxation were evaluated at 25 and 35°C in isolated rabbit, ferret, and cat ventricular myocytes during twitches, caffeine-induced contractures in normal Tyrode solution, and caffeine-induced contractures in Na- and Ca-free solution. The time course of intracellular [Ca] decline during these contractions in rabbit ventricular myocytes allowed estimates of the relative contributions of the sarcoplasmic reticulum (SR) Ca pump, Na/Ca exchange, sarcolemmal Ca pump, and the mitochondrial calcium uniporter (with the latter two considered together as 'slow mechanisms'). The percent contributions of the SR Ca pump, the Na/Ca exchange, and the slow mechanisms were 70, 27, and 3% at 25°C and 74, 23, and 3% at 35°C. Warming from 25 to 35°C decreases twitch contractions in rabbit and ferret myocytes and caffeine-induced contractures in normal Tyrode solution and Na- and Ca-free solution in all species. In contrast, in cat myocytes warming increased twitches, possibly because of a stronger effect of temperature on Ca influx. We conclude that increased temperature accelerates all of the Ca transport systems involved in relaxation. Despite large changes in each Ca transport system with warming, the relative contributions during relaxation remain similar at physiological temperature.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 270 |
| Issue number | 5 39-5 |
| State | Published - 1996 |
| Externally published | Yes |
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Keywords
- cardiac muscle
- mitochondria
- Na/Ca exchanger
- sarcolemmal Ca pump
- sarcoplasmic reticulum
ASJC Scopus subject areas
- Physiology
- Physiology (medical)
Cite this
Temperature and relative contributions of Ca transport systems in cardiac myocyte relaxation. / Puglisi, José L.; Bassani, Rosana A.; Bassani, José W M; Amin, Jatin N.; Bers, Donald M.
In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 270, No. 5 39-5, 1996.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Temperature and relative contributions of Ca transport systems in cardiac myocyte relaxation
AU - Puglisi, José L.
AU - Bassani, Rosana A.
AU - Bassani, José W M
AU - Amin, Jatin N.
AU - Bers, Donald M
PY - 1996
Y1 - 1996
N2 - The relative contributions of the different Ca transport systems involved in cardiac relaxation were evaluated at 25 and 35°C in isolated rabbit, ferret, and cat ventricular myocytes during twitches, caffeine-induced contractures in normal Tyrode solution, and caffeine-induced contractures in Na- and Ca-free solution. The time course of intracellular [Ca] decline during these contractions in rabbit ventricular myocytes allowed estimates of the relative contributions of the sarcoplasmic reticulum (SR) Ca pump, Na/Ca exchange, sarcolemmal Ca pump, and the mitochondrial calcium uniporter (with the latter two considered together as 'slow mechanisms'). The percent contributions of the SR Ca pump, the Na/Ca exchange, and the slow mechanisms were 70, 27, and 3% at 25°C and 74, 23, and 3% at 35°C. Warming from 25 to 35°C decreases twitch contractions in rabbit and ferret myocytes and caffeine-induced contractures in normal Tyrode solution and Na- and Ca-free solution in all species. In contrast, in cat myocytes warming increased twitches, possibly because of a stronger effect of temperature on Ca influx. We conclude that increased temperature accelerates all of the Ca transport systems involved in relaxation. Despite large changes in each Ca transport system with warming, the relative contributions during relaxation remain similar at physiological temperature.
AB - The relative contributions of the different Ca transport systems involved in cardiac relaxation were evaluated at 25 and 35°C in isolated rabbit, ferret, and cat ventricular myocytes during twitches, caffeine-induced contractures in normal Tyrode solution, and caffeine-induced contractures in Na- and Ca-free solution. The time course of intracellular [Ca] decline during these contractions in rabbit ventricular myocytes allowed estimates of the relative contributions of the sarcoplasmic reticulum (SR) Ca pump, Na/Ca exchange, sarcolemmal Ca pump, and the mitochondrial calcium uniporter (with the latter two considered together as 'slow mechanisms'). The percent contributions of the SR Ca pump, the Na/Ca exchange, and the slow mechanisms were 70, 27, and 3% at 25°C and 74, 23, and 3% at 35°C. Warming from 25 to 35°C decreases twitch contractions in rabbit and ferret myocytes and caffeine-induced contractures in normal Tyrode solution and Na- and Ca-free solution in all species. In contrast, in cat myocytes warming increased twitches, possibly because of a stronger effect of temperature on Ca influx. We conclude that increased temperature accelerates all of the Ca transport systems involved in relaxation. Despite large changes in each Ca transport system with warming, the relative contributions during relaxation remain similar at physiological temperature.
KW - cardiac muscle
KW - mitochondria
KW - Na/Ca exchanger
KW - sarcolemmal Ca pump
KW - sarcoplasmic reticulum
UR - http://www.scopus.com/inward/record.url?scp=0029884605&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029884605&partnerID=8YFLogxK
M3 - Article
C2 - 8928885
AN - SCOPUS:0029884605
VL - 270
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 5 39-5
ER -