Ca²⁺-activated mechanisms in toxicity and programmed cell death

Rapid development in the understanding of the role of the calcium ion in signal transduction and regulation of physiological processes has occurred during the last decade because of significant improvements both in analytical approaches and in general understanding of signal transduction mechanisms. Along with this increased knowledge has come the recognition that disturbances in the intracellular Ca²⁺ homeostasis can be central to a variety of toxicological and pathological processes. We now know of several potential mechanisms whereby changes in intracellular free calcium can activate cytotoxic mechanisms. In this article, we summarize the potential role of these processes in cell killing.