THE ROLE OF CALCIUM IN APOPTOSIS

One general signalling mechanism used to transfer the information deli vered by agonists into appropriate intracellular compartments involves the rapid redistribution of ionised calcium throughout the cell, whic h results in transient elevations of the cytosolic free Ca2+ concentra tion. Various physiological stimuli increase [Ca2+], transiently and, thereby, induce cellular responses. However, under pathological condit ions, changes of [Ca2+], are generally more pronounced and sustained. Marked elevations of [Ca2+], activate hydrolytic enzymes, lead to exag gerated energy expenditure, impair energy production, initiate cytoske letal degradation, and ultimately result in cell death. Such Ca2+-indu ced cytotoxicity may play a major role in several diseases, including neuropathological conditions such as chronic neurodegenerative disease s and acute neuronal losses (e.g. in stroke).