What is calcium buffering?

Calcium buffering is the process of regulating the free calcium ion concentration within a cell or tissue. It is crucial for normal cellular function, as excess calcium can cause cellular damage. Calcium buffering involves several mechanisms, including calcium-uptake by calcium-binding proteins, extrusion from the cell, and storage in intracellular compartments. The main calcium-binding proteins involved in calcium buffering are calmodulin and parvalbumin. In addition, the cell membrane contains calcium-ATPases that use energy to expel excess calcium from the cell. Calcium buffering is particularly important in excitable cells such as neurons and muscle cells, where excessive calcium levels can lead to aberrant activity and dysfunction. Several diseases are associated with impaired calcium buffering, including Alzheimer's disease, Parkinson's disease, and cardiac arrhythmias.