Mitochondrial calcium regulation during and following contractions in skeletal muscle

Abstract

In skeletal muscle, resting cytosolic Ca 2+ concentration ([Ca 2+ ] cyto) homeostasis is exquisitely regulated by Ca 2+ transport across the sarcolemmal, mitochondrial and sarcoplas-mic reticulum (SR) membranes. Specifically, skeletal muscle contractile function is critically dependent on effective SR Ca 2+ handling. However, more recent studies have revealed that mi-tochondria are essentially involved in [Ca 2+ ] cyto homeostasis during and following muscle contractions. We recently provided substantial support for the mitochondria as a major site for Ca 2+ 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 [Ca 2+ ] cyto regulation in vivo during and following muscle contractions.