Tissue-specific modulation of the mitochondrial calcium uniporter by magnesium ions

• Published in: FEBS letters 1985-04, Vol.183 (2), p.260-264
• Main Authors: Favaron, Marco, Bernardi, Paolo
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; calcium; Calcium Channels; Calcium-Binding Proteins - metabolism; Cell physiology; Fundamental and applied biological sciences. Psychology; Heart; Kidney; Kidney - metabolism; Kinetics; Liver; magnesium; Magnesium - pharmacology; Magnesium effect; Membrane and intracellular transports; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Mitochondria, Heart - metabolism; Mitochondria, Liver - metabolism; Mitochondrial calcium uptake; Molecular and cellular biology; pCao and pMgo , -log [Ca2+] and -log [Mg2+] outside the mitochondria; Rats; Δg̃mCa, Ca2+ electrochemical gradient; Δψ, membrane potential
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(85)80789-4

This paper analyzes the kinetics of the Ca 2+ uniporter of mitochondria from rat heart, kidney and liver operating in a range of Ca 2+ concentrations near the steady-state value (1–4μM). Heart mitochondria exhibit the lowest activity, and physiological Mg 2+ concentrations inhibit the mitochondrial Ca 2+ uniporter by approx. 50% in heart and kidney, and by 20% in liver. At physiological Ca 2+ and Mg 2+ concentrations the external free Ca 2+ maintained by respiring mitochondria in vitro is higher in heart and kidney with respect to liver mitochondria. This behaviour could represent an adaptation of different mitochondria to their specific intracellular environment.