Myocardial acidosis, as during ischemia, profoundly modifies excitation-contraction mechanisms. The decreased myofilament sensitivity to Ca2+ reduces contractility regardless of an intracellular accumulation of Ca2+. To determine the source for this increase in Ca2+ we evaluated the effect of acidosis on diastolic [Ca2+] and mitochondrial [Ca2+]. We used single cardiac cells loaded with the fluorescent probes, indo-1 for Ca2+ and SNARF-1 for pH. Acidosis increases [Ca2+] both in cytosol and mitochondria. The cytosolic accumulation depends, most likely, on an active release from mitochondria. A competition among Ca2+ and H+ ions may, instead, explains the increase in mitochondrial [Ca2+].
Gambassi, G., Capogrossi, M., [Acidosis is associated with an intracellular accumulation of Ca2+. Its role in the modulation of myocardial contractility], <<CARDIOLOGIA>>, 1992; 37 (8): 587-589 [http://hdl.handle.net/10807/37348]
[Acidosis is associated with an intracellular accumulation of Ca2+. Its role in the modulation of myocardial contractility]
Gambassi, Giovanni;
1992
Abstract
Myocardial acidosis, as during ischemia, profoundly modifies excitation-contraction mechanisms. The decreased myofilament sensitivity to Ca2+ reduces contractility regardless of an intracellular accumulation of Ca2+. To determine the source for this increase in Ca2+ we evaluated the effect of acidosis on diastolic [Ca2+] and mitochondrial [Ca2+]. We used single cardiac cells loaded with the fluorescent probes, indo-1 for Ca2+ and SNARF-1 for pH. Acidosis increases [Ca2+] both in cytosol and mitochondria. The cytosolic accumulation depends, most likely, on an active release from mitochondria. A competition among Ca2+ and H+ ions may, instead, explains the increase in mitochondrial [Ca2+].I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.