Mitochondrial calcium regulation during and following contractions in skeletal muscle

In skeletal muscle, resting cytosolic Ca2+ concentration ([Ca2+]cyto) homeostasis is exquisitely regulated by Ca2+ transport across the sarcolemmal, mitochondrial and sarcoplasmic reticulum (SR) membranes. Specifically, skeletal muscle contractile function is critically dependent on effective SR Ca2+ handling. However, more recent studies have revealed that mitochondria are essentially involved in [Ca2+]cyto homeostasis during and following muscle contractions. We recently provided substantial support for the mitochondria as a major site for Ca2+ sequestration in skeletal muscle during recovery from fatiguing tetanic contractions under in vivo conditions. This review provides an overview of the role of skeletal muscle mitochondria in [Ca2+]cyto regulation in vivo during and following muscle contractions.