[Acidosis is associated with an intracellular accumulation of Ca2+. Its role in the modulation of myocardial contractility].

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+].

• Authors: G Gambassi, M C Capogrossi
• Journal: Cardiologia (Rome, Italy) (Cardiologia) Vol. 37 Issue 8 Pg. 587-9 (Aug 1992) ISSN: 0393-1978 [Print] Italy
• Vernacular Title: L'acidosi è associata ad un accumulo intracellulare di Ca2+. Ruolo nella modulazione della contrattilità miocardica.
• PMID: 1486581 (Publication Type: Journal Article)

Chemical References

• Benzopyrans
• Fluorescent Dyes
• Indoles
• SNARF dye
• indo-1
• Calcium

Topics

• Acidosis (physiopathology)
• Animals
• Benzopyrans
• Calcium (physiology)
• Cardiomyopathies (physiopathology)
• Fluorescence
• Fluorescent Dyes
• Hydrogen-Ion Concentration
• In Vitro Techniques
• Indoles
• Mitochondria, Heart (physiology)
• Myocardial Contraction (physiology)
• Rats